The Linux kernel has been updated for some new hardware that still includes the AMD Van Gogh APU, which is currently only used in the Steam Deck. Popular speculation is that Valve will release an updated Steam Deck, one that still uses the same APU (so same performance), but had other changes to the hardware. Possibly different screen, larger battery, etc.
Possible code name for the hardware is Galileo.
If you want more/better info, I'd recommend reading the linked article.
That’s not wild speculation, just normal speculation. It’d also maybe possible that the refreshed sephiroth chip that’s also been found recently could be used in both a deck refresh and deckard.
Valve does tend to re-use hardware between different products when it makes sense anyways. The watchman dongle for SteamVR controller data was just a Steam Controller dongle. You can actually flash the firmwares between each.