Well, that’s unfortunate
It appears that Valve will now allow companies to restrict their games on Steam from being gifted or traded to users in different regions. The AllowCrossRegionTradingAndGifting flag has been found in the database entry for Metal Gear Rising: Revengeance on Steamdb (it’s a “no.”)
This is a major disappointment for folks simply wanting to give a game to their friend, but given the price and content differences between regions, it’s no surprise that Steam users have been using region-free game trading/gifting to their advantage. It is worth pointing out that this does not affect retail keys and as of now only applies to South America and Eastern Europe.