A recent SteamOS beta update mentions support for the extra keys of the Asus ROG Ally. This hinted that third-party handhelds could get official support for the operating system that runs on Steam Deck. Valve has now said that the team is "making steady progress" on adding official support for other gaming handhelds.https://www.notebookcheck.net/Valve-says-official-SteamOS-support-for-a-gaming-handheld-other-than-Steam-Deck-is-on-its-way.875797.0.html
So Steam Deck 2 will be released right after Half-Life 3