I believe the Steam Deck has a different frame for the OLED in such a slight way that an OLED screen (that isn’t specifically made for the LCD model anyway) won’t fit or something like that.
I have an LCD and looked into it at one point, but I’m sure you can find it if needed.
Can’t you buy a replacement screen and upgrade it yourself?
Edit: looks like ifixit just has led screens.
I believe the Steam Deck has a different frame for the OLED in such a slight way that an OLED screen (that isn’t specifically made for the LCD model anyway) won’t fit or something like that.
I have an LCD and looked into it at one point, but I’m sure you can find it if needed.