Perfect and love the early community support!
Short story... ArcGIS Maps shows as the name since we have to use a short and long name. The short name also populates the app bar on the left as well as the name in the catalog, yet the long name is listed as ArcGIS for Teams and follows our other ArcGIS for Microsoft 365 naming conventions for Office, SharePoint, and Power BI.
Cheers,
Andrew