For the most part, not as far as I can tell.

It's always possible that some guy involved in hiring will have a hard spot for a particular regional, typically because that regional "stole" flying that "belonged" to his regional back in the day. I've heard anecdotal stories, but that's all.

If anything I'd be more worried about being non-alpa, ie better to work at an alpa bottom feeder than a non-alpa non-bottom feeder.

But that would be absolutely last on my list of criteria, behind QOL, geography, and pay.