I mean, look. I thought yamato was joining too, but if she isn't doesnt that mean the subversion guys were right? You can't get mad at them because I mean, they were literally correct
It wouldn't be a subversion though. Yamato was, imo, at no point, written to be joining the straw hat crew. It looked like she was, but it you poked at it, you'd see cracks appear that Yamato Stans would insist were inconsequential and meant nothing.
"Yamato saw momo can protect Wano so she'll leave" - yeah, Yamato saw something all right
"Yamato's dream is to live like Oden," - unless you mean get boiled in a pot by Buggy, there's something more than copying him.
There's also the whole "Yamato, son of Kaido" thing, with the Kanabo and similar fighting style paired with Momo who has Kaido's body. There has always been a very strong argument for Yamato to stay back. And the counter argument has always been: "lol you're dumb, you just like carrot." So now that the spoilers point towards that way, people are getting mad upset.