A bit too obvious for yamato (not saying she won't join). I think Oda playing us right now make us think Yamato is the only candidate. Let think about this, one piece magazine telling us there one place available for the crew just after a super cool character ask to be on the crew. Like they could rectify that way before yamato apparence. Sound sketchy for me.
I'll try to explain it...
Oda is just trying to hide the fact about Yamato being a character with the exclusive use of defeating Kaido...So to do not make us feel like the character is just for this, he has created a 2 alternative plots for the character...
1- is the plot of "i'm Oden", this plot it's just the progress line of the character to NOT sail with the Mugis, having a character progression.
2- Is the plot of "I'll sail with the Mugis" it's fully linked to the diary and the Oden role that she think that has to live...
These 2 Plotlines thogether are a smoke-screen(Or wall idk how to say it XD) for the fans to hide the real use of Yamato. She/He'll one of the main reasons of Kaido's defeat. When you think on Yamato, you think on a Strawhat Candidate because it's one of the firsts things we saw her saying, she wanted to go with the Mugis because she couldn't sail with Ace XD
That was a smoke-screen to do not make us realize the real narrative use of Yamato.
Yamato is in Fact a Lola 2.0, and at the end or the Arc she will have her own Adventure...
At least IMO ofc.