I don't actually mind that leaked synopsis being true as it's a completely new narrative setup for a Predator film. I like that it doesn't sound like a rehash of the other films because, let's face it, they were somewhat basic.
In regards to Tremblay's character deciphering the Predator language - I'm with those who don't like the idea of it being the spoken language but I honestly don't mind the idea he's able to see something in the written language. There's plenty of different types of autism and I wont pretend to be an expert on the matter but my understanding is that there's some who are extremely focused on certain subjects so someone being autistic who has an intense interest in language really doesn't seem that much of a stretch.
He's another actor who I'm not familiar with but seems to have a lot of buzz and hype around him. By all accounts he's another talented actor and if that's the case, I'm very happy to have him aboard. I like that this cast seems to be about talent rather than flashy names.