Ticketmaster and Live Nation have destroyed the concert experience. But it didn’t use to be this way. Today, Oasis and Taylor Swift tickets might go for thousands of dollars, but back in 1955, you could see Elvis Presley in concert for less than the modern-day equivalent of $20.
If this is true, they’re effectively creating demand by removing a large set of seats from the initial offering pool. This means they can say “tickets are selling fast”, without lying if you include that they’re just referring to the set on sale right now, not the total number of tickets.
This does smell like false advertising though, but I wouldn’t put it past the cracked US legal system for this to be totally legal.