Hmmm...  Interestingly enough, about half of the BGC 'fics I've read have
authors who either ignore or deny the canonicality (?) of Bubblegum Crash!
I can't say one way or the other; I haven't seen it.  Does your view of
"rewriting history" insist that the same characters/events show up, or is
it all right to start mid-way through the story and just run however you
want from there?

The problem with Bubblegum Crash in this context is that it _itself_ tries to
write history, by making the boomers less advanced and making Priss forget
all about Sylvie and Anri.

You can explain this away (the RPG has tried to), but your explanation is going
to sound pretty lame.