The option to display 'username' or User Name' on item details etc (e.g. bobcat23 vs Bob Catlin).
As security becomes more pressing, it is important to keep user login details secure. ArcGIS Online, along with ArcGIS Enterprise, display the user's username on an item's details page.
This may appear minor, however, sharing of usernames can be an additional risk to security, but also if the username is crytpic it does not promote confidence in the end-user that the data is credible, regardless if it is being sourced from a specific agency's site.
Possibly providing agencies the option to show username (Abe_COE) or user Name (Abe Coughlin), maybe even with other details that an organization might like to share (e.g. position: GIS Manager).
I recognize that there might be the argument that sharing names is also an additional risk to security, or at least sharing of private information, however most of our names and positions at our organizations are publicly accessible.