Most builders will put a “sold” button on a property if a “buyer” says he’ll buy a place. If he changes his mind, then it will go back to an “available” pin. This is all before any contract is signed.
And then, even if it does go into contract, there are a surprising number of cancellations. Certainly more in the last year and a half than before.
Not saying that’s the case here, but always something to keep in mind (i.e. builder tactic to increase urgency).