My uni started doing that here in June (IIRC it coincided with the return of student athletes?) The goal is exactly what's described in the twitter thread you linked -- finding those asymptomatic folks before a big spread happens.

Anyway, now we have regular testing done on the three waste stations, one each for campus, neighborhoods north of campus and neighborhoods south of campus. Students are not in dorms yet. The neighborhoods to the north include the bulk of student apartments, and as you might guess, that wastestation has had the highest rates consistently since late July (as off-campus students started to return).

Students are supposed to start moving into the dorms in mid-Sept and we're supposed to be back F2F the week after that. The uni is using that wastewater data plus state-level data for their decision making.

We'll see how it goes.