This game was removed from Steam due to license expiration in January 2021. Is that an issue for availability on GOG? I want to make sure I grab the game before it disappears if so. Thanks to anyone that is in the know.

The game is probably still on GOG because it reached this store some time after the steam release. And when the devs signed a deal to sell it here it probably stated that the game would have to be kept on sale here for a period of "X" years before it could be removed.
Meaning that after the publishing deal time has expired there's a very high chance the game will be pulled from GOG as well. If you want to buy you should probably do it soon.