If you've been holding out hope that a Steam Deck OLED version might get a surprise release by Valve, you can probably rest easy for quite a while. Speaking to PC Gamer, Valve engineer Pierre-Loup Griffais plainly said it's not something they can quickly swap in for a new edition.
That's not because of any specific issue with a Steam Deck OLED versus the regular LCD version. Rather, according to Griffais, every single component in the Steam Deck is wholly connected to each other, which would make changing the screen quite tricky.
I think it would be a bigger amount of work than people are assuming it would be. I don't think we're discounting anything. But the idea that you could just swap in a new screen and be done—it would need more than that to be doable.
It's just something you have to plan ahead. When we were working on this screen, we made sure these could be supported, even if the refresh rate switching wasn't ready at release. It was really important to us that all that would be supported. So it's something that you need to keep in mind when you're evaluating and selecting possible options. It's about how you're designing the whole system and what's in between the screen and the SOC (system-on-a-chip).
While many fans have been salivating at the prospect of the far better and more accurate color reproduction allowed by OLED displays (even with handhelds, as seen with the PlayStation Vita and Nintendo Switch OLED), it sounds like it'll be a while before Valve can produce it. Chances are it could happen whenever a brand new version of the Steam Deck is released. Again, though, just a few days ago, Valve stated it wouldn't be happening any time soon.
While there are already more powerful handhelds, such as the AYANEO 2 and the upcoming AYANEO NEXT 2, Valve is keen to wait to release a next-generation Steam Deck until a significant horsepower increase can be achieved with new chips. There's no timeframe on when that might happen, but we can guess it might be at least a couple of years before a new Steam Deck is released.
Until then, Valve will continue using its software magic to squeeze the most out of its PC handheld. Just recently, they enabled ray tracing in DOOM Eternal, which is no small feat considering the hardware limitation of the Steam Deck.