What exactly do you all mean when you say "anime only ending"? Are you referring to something like the ending of the original Full Metal Alchemist anime (or Soul Eater)? Both anime had actual conclusions that deviated from the plot of the manga. Magi is not ending. At the end of episode 25 they announced that the second season will
begin this October. I don't know how much they changed from the manga,
but it can not have been that radical if they plan on continuing the anime. Code:Breaker has also continued, as an OVA series. If Shingeki is not popular enough, they won't animate everything until the end of the manga. That is common enough. Bleach, D. Gray Man, Reborn all were canceled before they could be completed. But an anime only ending, like the original Full Metal Alchemist, seems very unlikely.