Recently, the Hyperscale SIG created an infra ticket about a proposal to change the rpm 'vendor' macro to be more specific than 'CentOS' for pgks built on https://cbs.centos.org .
For details, you can read https://pagure.io/centos-infra/issue/621
I think it's a very good idea as we also started to show a difference between distro (/9-stream) vs SIGs (on mirror.stream.centos.org) so also doing that at the rpm level (already using a different gpg key anyway) would be easy enough to modify.
Here is our proposal : define the default value for that rpm macro to 'CentOS Community Build Service' instead of 'CentOS'.
It's also possible to request a specific override (what we tested with Hyperscale tags) and I'd even think it would be better to create directly each new tag with a common pattern like 'CentOS <sig_name> SIG' , which would be easy to automate when we have to create new tags.
This is just a Request for change, that we intent to implement next week, so if we don't have any negative feedback (we don't think people are actually parsing that field - yet - ) about this change, it will go live next week.