Please could you start releasing a detailed changelog / patch notes when you release ArcGIS Online updates?
At present ArcGIS Blog posts and other documentation on doc.arcgis.com are too siloed and not detailed enough to be a useful resource.
We frequently notice significant changes to how ArcGIS Online functions following an update and have frequently spent multiple days investigating what we believe are issues to eventually just surmise it's probably fine and probably just the update.
If updates were properly documented via a changelog / patch notes we'd have an authoritative resource to call upon instead of trying to scour 23(!) blog posts and countless bits of documentation.