I'd like to suggest adding Black Mesa and Half-Life: Alyx to the list of available games when uploading a map to the map vault.
There are a couple of maps for Black Mesa currently in the vault, and it's also available on Steam, which is why I think it should be added.
While there are no maps for Half-Life: Alyx that I have seen, it is an official Half-Life game, and there might be maps added for it in the future, so it should be added for those reasons. Also, Half-Life: Blue Shift is currently listed, and it has 0 maps made for it on this site
There are a couple other Valve or Valve related games that have been released since Counter-Strike: Global Offensive that might also be considered for being added to the map vault, but these are the ones I think have the most reasons to be added right now, especially since they're both related to the Half-Life series.