With Big Mom gone, there's nobody to protect Katakuri from the other yonko and marines who would be eager to invade his territory and plunder it. Yeah, the BMP are strong, but without Big Mom herself, they aren't a yonko crew.
That's why I think Kata will ally with Shanks. I see Shanks going out of his way to make peace with him, offering to help him recover Pudding and maybe even take revenge against Kid and Law for beating Big Mom.
I think Shanks would be the most likely to do that, just because out of all of the yonko, Shanks is the one who's crew has always been emphasized. So I think it would make a lot of sense for the red hair pirates to absorb the big mom pirates and be one of the strongest pirate crews in one piece.
Kata could go to Luffy, but I feel like Oda wouldn't do that, since Luffy has enough allies. Plus most of the BMP hate Luffy for what he did during the WCI arc. Shanks seems like the most neutral yonko, so I think he's probably the one they'd have the least qualms about joining.
That's why I think Kata will ally with Shanks. I see Shanks going out of his way to make peace with him, offering to help him recover Pudding and maybe even take revenge against Kid and Law for beating Big Mom.
I think Shanks would be the most likely to do that, just because out of all of the yonko, Shanks is the one who's crew has always been emphasized. So I think it would make a lot of sense for the red hair pirates to absorb the big mom pirates and be one of the strongest pirate crews in one piece.
Kata could go to Luffy, but I feel like Oda wouldn't do that, since Luffy has enough allies. Plus most of the BMP hate Luffy for what he did during the WCI arc. Shanks seems like the most neutral yonko, so I think he's probably the one they'd have the least qualms about joining.

