I'm currently monitoring the security advisories for AlmaLinux packages by subscribing your email security list. Nonetheless, I'm an avid supporter of RSS-like delivering systems. Additionally, I think it is a perfect match for structured information such as your security advisories!

Is an RSS Feed something that could be provided for the information on https://errata.almalinux.org/ ?

You're not the first person to request this, and I agree it should be something offered. If there is more interest shown on this GitHub issue, perhaps it can get prioritized :).

https://github.com/AlmaLinux/errata-email-notifications/issues/9