No, shouldn’t be a huge deal as long as you are honest why. Ive been in the regionals for a few years, made a lateral move myself (not in Indoc) and it’s never been an issue getting on with another regional...most of the people I fly with tell me they’ve been other regionals.
Plus who cares what people think, make sure you’re at a company you’re going to be happy at that also makes the most sense. If anyone asks down the road tell them the truth. Good luck!
Good luck!