The shit storm from Europe didn't change their decision to lock Arena 1.
It didn't make them not lock Arena 1, but I think it made them not lock Ultimax.
I think Atlus US probably took a lot more notice of the response to the region lock than a lot of people expect. They are, after all, a company who thrives on their reputation, and it made them look really bad.
I think it's safe to say that it was Atlus JP who chose to lock the first game, and I think this time around Atlus US likely really pushed to make Ultimax region free.
Make it happen Atlus
I'M ON IT.
*runs to grab pens*