I absolutely think the new station will be built. The construction permit was issued back in September 2022.
I was happy when I read about this. I have nothing against Marquee Broadcasting, but I'd never even heard of them before they got the construction permit. On the other hand, I've definitely heard of Gray. They are one of the largest station groups in the country and have affiliates with all of the Big Four networks and many stations I'm familiar with.
The question that still remains is what they will air. The station as-is has two distinct disadvantages. One, it's on VHF, which doesn't work as well for digital broadcasting. Two, the transmitter site is about 15 miles south of Provo at a height much lower than, for example, Farnsworth Peak. They'll be able to cover Utah County with no problem. Coverage of Salt Lake County should be OK. North of that, I'm not sure. I don't think they'd have a snowball's chance in hell of taking a Big Four network affiliation away from one of the incumbents. There are some diginets that don't currently have SLC clearance, but no major ones that I can think of. They could go the independent route, but with KMYU, KJZZ and (sorta) KUPX already doing the independent thing I don't know how much product is left.