Technically ... Circus Circus LV owned by MGM, though not part of their M Life players card program.

Yes, Las Vegas ownership has become very consolidated, including multi-property ownership by Red Rock Resorts (formerly Stations) and by Boyd Gaming too.
Even the downtown properties are consolidating in ownership.

As a consolation, if all 3 of the announced new casinos open on the Strip, it will be 3 more independent options --
Lucky Dragon (late 2016 ?), Resorts World (a Genting project) and Alon.