Regarding the weight issues, yes it is difficult to maintain it, specially if your body is growing and can't adapt to your supposedly weight categories. That's why there are different type of weight classes, so that boxer can fit where they height and body will go. Then go up another notch like what Manny did during his prime and beating large fighters. So for Jerwn, and it the news is true that he can't make the weight properly then it will be a very dangerous fight for him and most likely he might lost again. But if his team are good at working with him round the clock to check how his body is losing that weight, and not body mass, and then still retain his power at absolute peak prior to the fight then they do a good job and most likely Ancajas will have his revenge.
We make it a big issue and yet Ancajas can still make it to the weight requirement. I think what Ancajas has to focus is to improve his stamina, it's not the weight that is the problem but his Ancajas because if he gets tired easily, he will lose his power in the later rounds, and that's what happened in their first meeting.
Not sure if we are to blame that we are talking about the weight issues. Someone has brokered it to the media, maybe it was part of his team that tell is, or it was Jerwin who told it. So I would say that they started it. You can read it here:
Both Ancajas (33-2-2, 22 KO) and trainer Joven Jimenez claim that the weight cut was a major factor in Ancajas’ loss to Martinez, which saw him absorb more than 400 punches over 12 rounds.
https://www.badlefthook.com/2022/3/1/22956544/jerwin-ancajas-moving-bantamweight-upset-loss-fernando-martinez-boxing-news-2022So the issue is real and they have to look for ways that it won't happen in the rematch. So whether he can make the weight or not, we will see. And if he ever make the weight, can he rehydrate on time, that is the big question.