True, though as mentioned, given how the demons have been retconned since their first appearance, that would be surprising. After all, they were made the unfortunate victims of the Holy Wars, fighting for survival or under the control of others.
I don't think they were retconned or made into victims of the war. They're not portrayed as purely evil creatures anymore, but nothing about their destructive behavior and using other clans' souls as food has changed. Even the recent demon village was specifically formed by a small group who refused to participate in the war. Most demons still aren't very sympathetic, so I'd say it's more like they were fleshed out a bit to add some nuance to them.
Well I said he was wrong because according to Merlin in the previous series, most of the citizens of Camelot were saved. And apparently even some of those that had been hidden were shown surviving. So if Arthur fled at the end of the previous series, it wouldn't have been with just a few, unless a majority decided to remain in Liones. The story as told is quite different from what we know the reality of the situation was. There's also the implication that the demons were believed to have left sixteen years ago, but there apparently being more to it then that to the point that the sealing of them would be serious trouble, though perhaps that is solely based on Meliodas and his strength.
The giant graveyard in the ruins of Camelot that is shown in the movie confirms that there were quite a lot of casualties. If I recall correctly, Merlin didn't seem to know about the people living underground, which would explain how so many people ended up dying despite the fact that the Sins thought they had saved most of the citizens. You're probably correct in that some also decided to remain in Liones, since the alternative would have been to return to the ruins or the weird dimensional castle. I think the demons probably did actually leave after the war, since Gowther has apparently been watching over this one village for the last 16 years. I don't see why he would exclusively focus on this one if there were other villages as well.
Not really, if it's propaganda. We already had characters like Ironside publicly calling Liones evil and acting as if they're saving people from it. And it's not that much of a stretch considering the difference between this potential Holy War and the second Holy War is three goddesses. Them and the Sins were the only non-humans involved, so the overall argument would be the same. It's not complicated if it's suppose to be a twist. We've already been given several hints that the two are already in conflict and are currently attempting to gain an edge, having it be that they had previous clashed wouldn't be that convoluted and would lead to an explanation on why they're both gathering the means as they are. And I would say the previous series would still be affected negatively going from Arthur and the Sins being allies to them randomly being enemies without any triggering event. Additionally, assuming that the second Holy War is the trigger behind the way Arthur and his knights are acting would only make sense if they were just against the demons, but as we have seen, they're also against the giants and fairies, meaning something had to have cause them to become enemies.
Maybe I'm misunderstanding something about what you're saying, but the archangels and the Sins were not the only non-humans involved in the Holy War. The fairies and giants sent their own armies to fight alongside the Liones holy knights, and the demons of course also had their own army. You can see all four sides on the same battlefield in the chapter in which Ban uses the power of the Fountain to revive Elaine. The goddesses were the only ones who didn't have an entire army present, but even they had Elizabeth and the 4 archangels, so basically their entire elite forces sans the SD. That's quite a bit different from the Sins fighting Arthur on their own. That scenario also wouldn't explain why the Knights of Chaos have such a seething hatred towards the demons in particular. Ironside is entirely focused on the demons and there's also the difference with how Talisker tried to get Ordo to abandon to giants and fairies or to just destroy the Gorge to drive them out, while Ardbeg wanted to kill all the demons in the village. Arthur's knights believe in human supremacy, but seem to despise the demons much more than the other non-humans, which wouldn't really make sense if it was an alliance of all the clans that destroyed Camelot and drove Arthur's knights to this point.
A scenario in which Arthur and the Sins have clashed before isn't convoluted, and I could see that having happened. What is convoluted is this course of events in which Camelot was destroyed by the leader of the demons during the Holy War, and was then rebuilt later on even though we see Arthur opting to turn the ruins of the kingdom into a graveyard. Then another Holy War occurred, in which the same scenario happened to Camelot again, except not really because Meliodas wasn't the leader of the demons and the conflict probably didn't even involve the clans like the other Holy Wars. And somehow people like Anne and Donny end up with completely different accounts of the Holy War, depending on whether the Sins were fighting the demons or on the side of the demons, but people never realize that the stories don't match up at all even after 16 years. This would only be possible if Nakaba was deliberately misleading the audience by making characters give us contradictory information that conveniently isn't noticed by anyone in-universe, which sounds pretty convoluted in my book. Arthur and the Sins could have just clashed in a separate incident that has nothing to do with the Holy War, although you could take Gowther's reaction to Ardbeg story as evidence against that. Gowther didn't seem to know, at least not for sure, that it was Arthur who had been recruiting people like Ardbeg. It's hard to believe Gowther wouldn't know something so basic about Arthur's forces and behavior if they had fought him before and knew he was still hiding somewhere. Now if Arthur had simply disappeared after the events on NNT, it wouldn't be that surprising for Gowther to not know that Arthur has been preparing for battle.
I would assume that if there was an error with the timeline, that would have been corrected after the first time. Or not even mentioned, since we would already be aware when said Holy War took place. That we have it being repeated multiple times would suggest that it was on purpose, or an error made canon. Wasn't aware of that confusion with Nakaba's comment.
That's what you'd assume, but this is Nakaba we're talking about. I can totally see him mistaking the timeline since he apparently didn't even consider how confusing a statement like "the sequel takes place 16 years after NNT" would be if the last two chapters had two separate timeskips. The most logical assumption would be 16 years after the chapter in which the story ended, but that of course wasn't actually the case. If you're interested in Nakaba's initial comment about the timeline, you can find it and the first reactions to it here:
link.
