My understanding is that all that has changed has been the "Allow Cross Region Trading And Gifting" flag being set to "No" for all games on Steam. As such, it should only affect gifting, and not key redemption (one of our Russian friends can probably clarify this). That said, individual keys CAN be region-locked, and have been locked before, even if the game was not locked on Steam. That was under the old model, though. While I haven't heard of any changes to keys yet, it could be implemented later. Sorry I don't know more, but hopefully this helps.
Given the slow, deliberate way Valve's basically set out to destroy cross realm trading recently, I'd be very, very wary right now.
- PKB Mac likes this