@Shyning It's probably because Jeanne D'Arc is an easily recognizable female involved with battle. Like I just did a quick google search of famous female warriors and when looking at a bunch of lists that come up, if I didn't play FGO I wouldn't have recognized even half of the ones there.
@BokuNoGyro
I wanted to say that it might be a rule only for the prelims, but looking back there's a bunch of pokemon from other regions shown there too, so maybe the author just forgot or didn't want to include pokemon past gen 3 or something.
@ApolloX1209
I think him appearing is just a coincidence. I don't think he would have taken the time to remember exactly what Suri was doing at all times in the original timeline, especially considering how he hated her. And even if he did, since she is doing things differently this time she...