so we're all going to hold onto sequoia like we did snow leopard. only reason i'm not buying a new mac at the moment is because it would force me to upgrade.
the situation is absurd ..
fwiw switching to the sequoia beta channel in system settings killed the nag notifications for me (I believe the profile as defined in OP will stop all updates - which you probably don't want)
But you probably don't want to receive all and only beta updates either, which is what the beta channel will give you.
My historic "sticking points" have been macOS 9.1, 10.8, 10.13, & presently 13.2
I'm getting old enough that it's rational thinking: pre-AI/pre-Tahoe operating systems will be accompany me into death.