There's nothing on the W284BW construction permit that mandates any sort of test time, at least not that I can see. These days, the FCC doesn't really do that. You file for a CP with a technical showing that there won't be interference on paper (in this case, most critically to the north against WSPK), the FCC grants a CP based on that showing, you get automatic program test authority with the CP, and then it's up to other stations to decide whether there's real-world interference that justifies gathering listener testimony and making a complaint.
W284BW could file for its license to cover today if it wanted to, and barring any objections filed against the LTC, it could be fully licensed in a week or two. And even without a full license, it could run "regular" programming under program test authority.
I suspect what the "stunt" is really doing is giving potential lease tenants an opportunity to hear what the 1WTC signal does and where it does/doesn't go, and to make their decisions about whether to pay whatever Walia is going to be asking to lease the translator. As such, it will last until the ink is dry on a contract, whenever that happens. At least, that's my educated guess.