Those chips not supporting RV23 isn't super surprising, they were released in 2023 while RV23 was only ratified in 2024.
Ubuntu requiring RV23 however does surprise me (I admit I didn't read the article), that seems premature, but I suppose it's a good baseline going forward. Last time I looked at any of the chips none of them supported the V extension, and those that did were majority only supported the incompatible pre-standard version.