While it was partially used for anti-gun narrative (triggered bump stock ban), they were far more interested in memory holing it?

Why's that? Based on what I've found - it was a botched assassination attempt of the prince in SA who worked with Trump to arrest the corruption Saudi family shortly after the shooting.

Paddock was the patsy. And given his history, I'd guess he was an operative who was deep into the gun running game (tail wing # matched CIA run hangars, phantom girlfriend, spent time gambling money as quickly as possible to launder the proceeds). I'm guessing that he was handing over a big shipment to the folks who were there to pull off the hit, shit went south because Salman dipped out (tipped off?) and was in the right place and the wrong time.

Once he got evacc'ed from a different casino, the hitmen were stuck in the Mandalay w/ Paddock, probably told to execute him so they could pin the blame and then open fire from the penthouse to create pure chaos to cover their escape (which I'm guessing was done via chopper).