It is a bit head scratching, but I have no idea what goes into world wide logistics. And now in the states they are even offering refurbished Decks, so they certainly appear to have enough product at this point to open things up. But maybe they dont have enough to open them up without creating another multi-month long backlog they dont want?? Who knows
My personal and never-asked-for wish is fairly small - Backlit buttons. Id like the ABXY and Steam/start/select/Menu button to have a faint glow to them with a toggle on/off/dim in the menu. Maybe even the analog stick could glow where the current sticks are white.
For the gen pop I think the low hanging fruit of upgrades people would actually be interested in would be:
Beyond that its going to be niche improvements that some people may find interesting and others not so much: