Steam has now officially removed their first game from user libraries.

Can Steam games be removed from your library?

Thank you for contacting Steam Support. Games cannot be removed from a Steam account. You are free to uninstall the game (right-click on the game name and select "Delete local content") and change your game list to show only installed games.

Has Steam ever removed a game?

They're scams. In September of 2017, Valve removed 173 games from Steam, all from the same single developer.