Tbh, I've read
@playa4321 's theory
@Pantheos comments about Oden and I'm starting to actually wonder if its Toki's time powers too
Like pay attention the dialogue (assuming it's accurate): "I've wanted to meet you all!" "You've all aged quite a bit to!" It almost sounds like he's surprised they aged and that his intention here is to speak with them only, no expression or intention to fight Kaido. To me, in the middle of a battlefield, seems off, unless it truly is Toki using her powers to "project" Oden there temporarily.
For example we weren't actually given limitations on Toki's ability, but its possible Oden at some point met his subordinates 20 years in the future during his flashback. Then he goes back to tell Toki and give the prophecy.
Now, the question might be when this could happen, and the answer could be right before they go to fight Kaido, after Oden found out they lied to him while he danced. Its possible he knew his time before then and realized he couldn't change his future or at least explicitly refused to try.
Its also potentially means they won't tell him anything signficant, just a few sentimental words before Toki reveals herself too and explains how her powers work. I always felt "just" time travel by sending her body forward in timewas a little tame for Oda lol.
Now, barring how bad this can cause time travel inconsistencies, I could totally see it being the explanation because I still totally think the 1004 silhouette is Toki, which would explain how this is being done because she's already here in the future.
Edit: Then again, why the fake swords then? Maybe this doesn't make sense lmao