The iD editor for new users defaults to tick the "review requested" checkbox. JOSM users can enable that too, but I don't know if this is a default.
If I fully understand, without any digging through sourcecode, WhoDidIt processes changesets, so that information should be available when consuming upstream data.
Might that enhance user experience, if tiles containing such changesets get an icon, and corresponding changesets too in the listing shown, after the tile clicked?
Reasoning: WhoDidIt users are likely seasoned contributors. That might make them aware of newcomers looking for engagement with the community.