Not in so many worlds. But I do remember there being some hubbub about WotC confirming that, for example, Thaksis is Krynn’s version of Tiamat, not a separate character that shares a lot in common. I think the idea WotC was trying to go for there is that Krynn, Abeir, Athas, etc. are in fact MCU-style parallel versions of each other. The differences between those parallels are just much more significant than the differences between the various Earths in the Marvel and DC universes.
On the other hand, the fact that in Spelljammer they’re treated like different planets within the same cosmos throws a bit of a wrench in that. But the way I see it, Spelljammer kind of plays around with using fantasy logic to make space travel and interdimensional travel be one and the same.
Notably, infinity is weird and people struggle to really understand it. A lot of media that deals with the idea of infinite parallel worlds takes it as a given that if there are infinite worlds, a world for every possible variation must exist. So, for example, if we assume infinite parallel Earths exist, that must mean there’s an Earth where everything is the same, except I misspelled one word in this post. But that isn’t actually how infinity works. Infinity minus one is still infinity. There could easily be infinite parallel worlds without that infinite including a world like the one I just described.