Its probably a Half Life: Alyx sequel. Which is mega hype because that is the best VR game ever.
Spoiler:
! G-man unexpectedly plays a huge role in the game towards the end, to the point he's so powerful you're not sure he's human.!<
That plus Valve's next VR headset codenamed Deckard is gotta be right around the corner, with the controller leaks. Alyx released along side the Valve Index to show it off. Lastly the marketing info for SteamOS being show combined with rumors Deckard may be a stand alone VR headset, or an optional add-on.
I don't know if different clients/instances/communities could play a role in how those work, but I don't think I've ever really seen many working ones, at least as long as I've been using Voyager.
Alongside was poor word choice. Regardless Valve now has a history of releasing their own games for their new hardware. Alyx for the Index, and Aperture Desk Job for Steam Deck.
Cite? Its all just speculation... Even my comment is just speculation and prediction...