It would be wonderful if Esri had a simple website that shows with which version a new geoprocessing tool is added. Right now each version has a "whats new" page, but it would be great to see these pulled together into a single source so that we can verify that a tool exists or doesn't depending upon the version that the user has.
https://pro.arcgis.com/en/pro-app/latest/get-started/whats-new-in-arcgis-pro.htm
For example, the Wikipedia page on ArcGIS shows each version's release date and includes a link to the "what's new" page, but it would be great to see all of this information pulled together into a single searchable table.
https://en.wikipedia.org/wiki/ArcGIS