So you do that analysis. Two downstream distros of RHEL have said that they cannot continue to offer RHEL rebuilds/updates without substantial changes. That means that it is not possible to use CentOS stream alone to build RHEL packages. You are free to do all the analysis in the world.

It may incidentally be in some cases, but isn't guaranteed to be. Things don't necessarily flow back up from RHEL to CentOS stream, and even if they do in a general sense, it may not be sufficient to build the exact same tag that RHEL uses. Someone else mentioned that they were not able to build RHEL packages from CentOS stream.