I posted Feb 27 on how to switch 25.10.1 to the GA train. That version has been GA since, at least, that time.
If you got caught installing 25.10.2 or later, Sorry. There could be improvements to the process but it is also a case of users not reading the Documentation and the Software Status page.
TrueNAS company is used to their Enterprise customers and that is what is driving a lot of the development. Enterprise, usually, reads the release notes and decides if an upgrade in necessary or not. They test the EA or Developer software ahead of time, but not for production.
There were no Trains listed in 25.04 or earlier. The changes in 25.10 were supposed to be an improvement over that. Admins had to choose what updates to install. They got notified of available update but they were never ‘required’. There are still users out there with FreeNAS or early versions of TrueNAS. Support for FreeBSD 13 series should be dropped by freebsd.org any day now. There are still plenty of users that like and are staying on TrueNAS 13 (FreeBSD).
Updates have always been the choice of the Admin.