I think that both
@Obi-J Kenobi and
@mdmost make good points here. Note that I did not see the movie, but this is why I'm not the biggest fan of all this multiverse stuff - it gets weird and confusing with multiple versions of the same characters running around, trying to include all of the previous movies (even the BAD ones) - it can be frustrating I think and hurt the narrative.
That said, as Harrison Ford once said to a young Mark Hamill, "It's not that kind of movie." All of this timey-wimey stuff doesn't have to really make a lot of sense, expecially considering that it's a Deadpool movie that is already barely making sense as it is. That being the case, I'd give them a pass on it, though I still don't think it's the best way to tell a great story. Guardrails can be a good thing, you know?