Gregory's Server
Most of the time, the update to unlock the firmware wouldn't be especially technically complicated. It just requires access to the source code, build pipeline, and signing keys. So even if it's not kept in a central repo, if codified in law that it is a priority liability against the company assets if they declare bankruptcy to provide access to that information and fund a consultant to compile the firmware update, it wouldn't take all that long per device to compete.
Think when a company that holds toxic waste goes under - there's still liability to remediate it that carries on to whomever buys up the assets, and beyond some point it becomes a Superfund site to remediate.