To the best of my knowledge, Mozilla does not offer a mailing list for Firefox update notifications. However, regular releases are published on a specific schedule.

Although, it's important to note that the schedule is only valid for major releases (like updating Firefox 65 to Firefox 66). Minor fixes and updates of that nature (like Firefox 65 to Firefox 65.0.1) are published when needed and don't stick to a specific schedule.

Thank you! That will help. I also found the enterprise mailing list at mail.mozilla.org/listinfo/enterprise. They do post update notifications there. However, since it's a mailing list, one would get all the regular posts to it as well.