Even if the system boots properly, there's various critical systems that depend upon having the correct time. Say goodbye to things like HTTPS and SSL/TLS certificates.
Will the root-certificates still be trusted in 12 years? Will we largely use the same TLS versions? And if systems can be updated to account for that, shouldn't they also be able to be updated to deal with the timestamps limitation?
For comparison I've revived a decade old Axis PTZ camera recently and it can't be used with HTTPS because it only supports TLS 1.0 which is deprecated across the board these days lmao. The UI is so bugged out it's not possible to change the default username and password anymore.
There's two kinds of internet connected devices these days, those that keep getting updated and those that drift into incompatibility and die as the rest of the ecosystem evolves around them. If these supposed critical devices will still be in use in 12 years without any maintenance then they're unlikely to have any actual importance.