I'm in/out of LAS just about monthly - I think UA sees what I see. Literally zero convention traffic (LV is, I believe, convention destination #3 behind Chicago and Orlando) and a sea of empty E+ seats, with E- full. The traffic in/out of Las Vegas via road or air today is not LV's (or UA's) most profitable customers. Prospects of UC opening there soon I expect are slim.

The good news for LAS is that a Pink Box donuts is slated to open somewhere in the airport in 2021. I'm gonna find it

Edit: Now that I've looked into it a little more, it looks in 2019 they were talking about opening a Pink Box at LAS, but nothing became of it. Maybe Covid knocked some (donut) holes in their plans. They still mention a future LAS location at their website.