At this site:
it says "Rachel Finds out there's only one of her in the Multiverse from Uncanny X-Men #462" it cannot mean that every appearance we see Rachel in every backissue comics it's the same singular girl that we know from the 616? But how do Cross-Time Rachels differ from alt-reality Rachels - of which she says there is none? (Wonder how long it'll be before we learn if she's heard of Ruby Summers from X-factor run?)
I miss Dad and Dan.
I guess Claremont likes her being unique, while other writers in Exiles for example had alternate Rachels pop up, hence this being a strikeback against them.
Given the nature of parallel worlds and alternative timelines
Rachel being unique doesn't really make sense.