Steam seems to be enforcing their regional restrictions in such a way that they err on the side of overreaching.
The restrictions haven’t been revised, but Steam’s application may be going too far.
First, an explanation; Steam uses regional pricing, so that certain regions can buy games cheaper. To enforce regional prices, they have to place restrictions from those keys being bought outside those regions.
So, if you try to redeem a key from a different region, you’ll be told you need to activate it in the region it was meant for. Now, however, Steam has clarified further that they will place restrictions to users who try to push through with redeeming said keys.
Why is this an issue? Because some folks move, of course. You also won’t be able to play said games if you go on vacation.
The clincher? Steam Support is currently unable to make any changes to these restrictions, although it seems they will attempt workarounds if you need them.