I could see them do that, given that you actually break their TOS (even though they never really enforced it, but still), and it probably not having a big impact on them financially, since the PSN is available on large parts of the globe. And where it isn't, some probably still have an account anyway and wouldn't request a refund.
Here is a map where the PSN is available:
So yeah, full refunds for the people in the areas where the PSN isn't available, most prominently Africa, the Middle East, and Central Asia, should be an option at least.