Was in Vegas over 4th of July weekend, and it was very barren. Strip Clubs/Night Clubs are closed. Day/Night Pool Clubs (such as Marquee) have reduced capacity, and now require you to make reservations to attend. People are still visiting Vegas, and making the most of it, just don't expect to see it crowded as years past.
We will be in Vegas Labor Day Weekend, hosting a couple of out of state couples privately in an estate 20 minutes away from the strip, doing our thing. You can still have a good time, just make sure you use common sense and remembering the times we're currently in.
As far as lifestyle/hookups, that's still going on, as we know several bulls/couples that have been in/out of Vegas throughout the Summer hooking up. More of small gatherings, than full-blown lifestyle events at swing venues. As with anything, Vegas is what you make of it. Enjoy your trip!