I highly skeptical because almost every mass shooting we have has claims of a second shooter. If there was one, I don’t see why it wouldn’t be made known yet. The police could hear the gunshots from floors below the 32nd, so I’m pretty sure shots from another part of the hotel would have been reported and investigated.
Also, this was fairly well planned with location and logistics, so two shooters with this much planning wouldn’t let such a large pause in fire to occur. Hence why I said no “talking guns” where one shooter lays down fire and the other takes over while the first resets their aim or reloads. So with sustained fire for an entire magazine, one shooter would take over while the other reloads. Then you get a constant flow of rounds downrange, instead of a huge pause.
I’m not saying it’s out the realm of possibility for their to be two shooters, but my experience is telling me there’s no way I’ll believe it until actual proof comes out.