There's no need to adapt JJK 0 again in the series. It's true that Mugen Train was not needed neither, but in this case it would have 0 sense. A 26 episode season for Hidden Inventory and Shibuya will be enough. Shibuya needs more than 1 cour, but it does not need 2 cours.
It could be that there are people buying Phantome Seer volumes because they are now doing it with KNY and JJK and they think PS could be the next big thing. So they don't want to be late to the party like they did with the other two. These people probably doesn't buy the magazine so no vote...
2 cours for Goujo's Past and Shibuya Incident is ok. There's no need of 3 cours to adapt that. But I wonder what they'll do with Volume 0. An OVA would be perfect, but maybe they save it for a potential third season.
I've just read the title of KNY2. I would loved a 2-cour season, but I can see...
It would be great if we have MHA 5 in Spring-Summer cours, Chainsaw Man in Summer-Fall, KNT 2 in Fall-Winter, JJK 2 in Winter-Spring and MHA 6 in Spring-Summer.
Jujutsu has sold 3.797.405 copies.
And FYI:
Neverland - 1.368.632
Haikyuu - 1.280.004
Chainsaw - At least 1.059.758 (There are no numbers of November's last week)