Hi @sluke
I believe this change is happening based on the announcement on March 24th, 2021: https://experienceleague.adobe.com/docs/release-notes/experience-cloud/current.html?lang=en#appm which is about to take place in the upcoming release of Analytics.
Adobe, recommends using Federated IDs and enable Single Sign-on for organizations. This gives administrators more control over who can log in to the Experience Cloud solutions i.e. Analytics instead of restricting login from a particular IP address.
Here is a video for an overview of SSO and how it works: https://www.youtube.com/watch?v=bhZX8p0Ym0U
Hope this helps!