I'm one of the administrators for my eployer's Confluence Cloud site. Today, this feature was brought to our attention by a developer:

It looks like it currently applies automatically to most of our overview pages, but not all. It seems to inform on concurrent users, like in the editor, but in viewing mode.
I've been trying to look around the documentation blog and the "What's new" timeline, but haven't been able to find a description of something that looks like this feature. Is it some unannounced addition that we're in a rollout test for?
Anyway, the developer in question asked if there was any way to disable this, either on a (space and/or site) administration end, or to let individual users opt out from showing up in this view. I've scoured through all the settings panels I can find, but haven't found any indication of that either.
So, what is this, and can it be disabled?