I'm assuming it already exists due to the existence of pages like https://musicbrainz.org/tops/mb_top_stuff.html and https://stats.metabrainz.org, I'm just not positive of it. :)

Even if it's not collected though, it's data that they at least already have the ability to collect by simply flipping a switch, as opposed to spinning up a whole new ListenBrainz service and hoping it gains traction.