Nathan

My guess if he eats a third devil fruit it's going to be called the fish fish fruit model kraken which turns him into the kraken being the only devil fruit that allows the user to keep their ability to swim

You know this would actually be a pretty interesting storyline for Uaraka if they made a sequel for her to constantly be getting thoughts of toga and memories that aren't hers but are of toga's life and we could see Uaraka dealing with toga in her head which could make a fun heartwarming and sad story with Uaraka going around trying to do the things toga never got to do when she was alive

No, if they made a sequel to MHA it would have to be focusing on our former class a students as pro heroes and it's going to be really tough to show all of them while showing new hero students now yeah it would be interesting if we would occasionally see the new hero students, but I think it'd be more interesting but I'm too stretch away from school and how they all are handling being pro heroes. Now instead of UA I can see 1A taking place in the dorms that they stayed in during the final war one day using that as their new HQ to do various things such as training and dispatching heroes.

I say that if he wants to make sure his fans don't leave him yes, because while yeah it could be nice for a new start, he does run the risk of losing his fans due to not liking the idea of a new series, those who dislike the new manga's genre, or they just don't enjoy the new story. Now yes this can bring in new fans for Horikoshi, but it risks him losing his former fans which is the last thing you want to do as a writer. Now the biggest risk of him making a new series is that he has so long to decide weather he continues with this new manga, or he returns to My hero before people lose interest in both of them. Luckily he did end MHA in a place for him to continue the story, but the longest he can wait to return can't be longer than 2 years, because after that it's too long for a return because by then most people gave up on a continuation of the story. And at that point he's gonna be stuck with that new series weather it's good or total garbage