This is a HUGE stretch, but it makes a bit of sense to me
After watching odens flashback for the second time, i began theorizing the whole laughtale scene, and i came up with something that may tie together rogers interaction at fishman island and post laughtale.
So, after roger found the onepiece, he talked about how he was “too early”, meaning he was likely talking about the “next joyboy”, who he thought was going to be ace, but i feel like he knew about luffy somehow, especially in the way he was talking. So, what if the onepiece is just a poneglyph, talking about the whole void century and joyboys story, which would explain why oden was so invested in it as well. It talked about all the hardships and how strong joyboy became, to the point where he could see hundreds of years into the future, seeing luffy carrying on his will and being the only other person to unlock the full potential of the fruit and finally take down the government once and for all. This information was shared with toki by joyboy himself, who, before the big battle, sent herself to the future to see her home before his return to prepare the people of wano for the future. Roger, reading about the past, knew that he was too early to be here, and realized there was a different reason for him to be there, he knew we wasnt the one to take the government down, he didnt care about that as much as luffy, all he wanted was adventure, so after disbanning the crew, roger made sure his crew was sent to different checkpoints waiting for luffys arrival to make sure he is ready for that battle against the government that roger read about. Now, for toki, i believe she was originally there to protect wano, but seeing oden and his group he formed, she decided to go back to wano and make sure they were ready before sending them to the time where it mattered. While toki is presumably dead, i believe she is actually waiting for luffys arrival at laughtale to show him what really happened. Luffy will likely arrive at laughtale before the battle, so she will have to show him what he will have to surpass in order to win.
That is my theory