Alright, now onto the good stuff. In his tweet confirming the news that he is directing Predator 5, Trachtenberg referenced the fact that he'd been keeping the movie a secret and had a plan for how the project would be revealed that didn't involve an announcement in Deadline. It wasn't long after that fans began putting the pieces of this plan together.
In 2019, Discussing Film reported that Trachtenberg was working on a new project titled Skulls, which was said to be about "a Comanche woman who goes against gender norms and traditions to become a warrior." That announcement didn't raise any flags at the time. But once the news that Trachtenberg was attached to Predator 5 dropped, AVP Galaxy and other sites speculated that Skulls was likely a codename for Predator 5 used to keep the true nature of the project a secret. Considering the other Predator movies have taken place in modern settings, it's easy to see how, if marketed correctly, audiences wouldn't immediately guess a movie about an indigenous woman set in the past was the latest entry in the franchise.
Now, the Skulls-Predator 5 connection hasn't been officially confirmed by Trachtenberg, but the fact that both movies are being made for the same studio and have the same screenwriter attached makes the theory seem very likely. We will have to wait for more official details to confirm these rumors, but if they are true, it should make for a very intriguing new installment in the franchise.