Soulbonding

I was reading a description of another system, and there were several mentions of members deviating from canon, not to mention traditional fanon. My question about this is: aren't all soulbonds really AU? Unless the bonder in question was originally part of their story, isn't it outside canon's realm that the two should meet in every single case? Isn't this especially true for soulbonds that have learned to front and are now interacting with earth, a world they might never have known before? And, finally, if this is the case, why are so many of us worried about being perceived as out of character? Everyone changes in response to changing circumstances. It would only be logical we do, too.

~ Obi-Wan