Every update that goes into CentOS Stream is not a "proposed update", it is an update that has gone through the entire QA process and is scheduled to go into the next RHEL minor release. It's the same as Debian, except that Debian has no other "more stable" point release branch, it just has the one that updates flow into after being tested.
I might be misunderstanding what you're saying, but Debian Stable has LTS versions, which will give you your stable system for a longer period of time.