This is most likely a legislative issue with NHTSA, I don't think they have a mechanism by which they can enforce a software update since the concept didn't exist when recalls were first implemented.
Why not? At the end of the day its a binary check box on the paper that you had the fix. Whether that fix was a software update or a new piece of hardware should be irrelevant.
Inaccuracy is inaccuracy no matter in which direction. If an outdated law made it easier for Tesla PR to spin something in a positive light, would you consider that an issue?
Electing congresspeople who actually stay on top of the expert consensus in various regulated fields is the only way the frameworks themselves can be improved.