Valve will loose competition quick if they wait that long. Asus is probably already working on a rog ally 2, legion go came out and is packed with features. Aleast release a steam deck with the newest GPU, ram and a 1080P 120hz or 144hz oled or QHD 500 nit screen within a year or so from now.
The SD is literally still selling better than the competition despite having a weaker SoC the SD has sold multiple millions of units while the last update we had for the Ally was 500K back in August. Even looking at the Z1 Extreme in the Ally and Go the performance uplift isn’t that crazy and you lose your battery life for that small uplift. Also no putting a 1080p or greater screen on these devices is silly you’re not going to run many games at that resolution and if you are you’ll be sacrificing battery life, performance or both.
If the SD isn’t the device for you that’s fine that’s what competition is for but myself and many others are happy with the SD and only want to see a true successor when the technology is there to back it without tanking battery life.