Valve itself doesn't, but game devs on Steam regularly revoke keys:
2019 article: SteamWatch - The Steam Key Revoking System is a Problem | TechRaptor
2025 update from the same author: SteamWatch - The Steam Key Revoking System is a Problem (V.2)
another report from 2024: Steam Publisher Revokes Game Access, Leaves Customers Empty-Handed