Sony required the PSN account, which Arrowhead didn’t enforce. Clearly they didn’t want it either. Until Sony forced them to enforce it. Arrowheads mistake was not enforcing it the entire time. They tried to be the good guys by ignoring the Sony requirement and when this was no longer possible ended up with an apparent bait and switch. If they just listened to Sony and required it the entire time, they wouldn’t get into this situation.

So yes, they should give refunds.