Here's my two cents.
Many of the original Steam Deck users initially gravitated towards the device for its promise of a "cheap" and convenient, console-like PC gaming experience. Now, with the impending release of the new OLED model, the online marketplaces have been inundated with a huge amount of used Decks at crazy low prices. So, considering how good (for the price) the Steam hardware still is in 2023, and how close we are to Xmas is not too much of a stretch to think that both new and used consoles will have a huge sell.
So what?
Well, i do believe that this further grow may actually push the game developers to release more "deck optimized" games in 2024. The pressure is already there and with more users this trend may actually grow.
What do you think?
Unless their production costs are vastly cheaper for the old model, I give it maybe 6 months before they replace the 256 LCD sku with an OLED version. They probably know they wouldn't be able to keep up with releasing the entire lineup at once and want to get just a bit more use out of the existing lcd sku production line and supply chain (using up already purchased components and running out contracts) before they shutter it.
Definitely, it makes sense to only keep making the new internal components past the short term