Well the resolution is still an advantage for the Deck HD. Personally the biggest issue for me that prevents me from upgrading my own OG Steam Deck is that you have to flash the firmware to use the Deck HD, not that SD OLED came out.

Could be. TBH it did sound silly from the first place that they opted for 64gb eMMC instead of actual SSD, when it was in fact just an NVMe drive that has eMMC module instead of NAND flash dies. They probably had to go extra length to procure these wierd storages instead of just buyng 64gb SSDs which were already cheap.