Source is KeplerL2, who is generally considered a reliable source for insider hardware info, particularly on AMD GPU hardware and AMD SoC for consoles.
Previously I would have personally estimated Steam Deck 2 to release mid 2026-early 2027, but the recent info about an upcoming Steam Machine made me think that maybe I should push back that estimate.
Of course even if we assume this is reliable insider info, a lot can change in couple years, so things can definitely change.
I see plenty space to upgrade on battery relates masters, more deficiente processors would certainly allow that, whilst also enabling the deck to be used in 4K screens whilst docked with an actual decent performance and graphics.
Battery doesn’t have as much of an upgrade path as people think - you add more cells / energy in the same space, and you get the cause of those Samsung phone fires. It more commonly comes from processor efficiency improvements, which is hard when that’s mostly the domain of whoever coded the Windows-based video game you’re playing.
If it helps: Look up TDP customizations for your favorite games to play on Deck.