I interpreted him referencing the BFI screening as just proof that Lucasfilm/Disney is no longer shying away from the theatrical versions, or pretending they don’t exist like Lucas did for decades. They even falsely claimed the original negatives no longer existed, or were permanently modified in the 90s. These leaks prove that was a load of BS, which everyone suspected anyway.
I agree with him that Lucasfilm allowing the print to be screened, and having Kathleen Kennedy there to introduce it (she even made a comment about George’s constant tinkering) is telling, and was pretty surprising.
He also mentions that they’re likely using that IB Technicolor print as a color reference for their re-master, which the leaked documents also seem to confirm.
As for what Bill knows and when he knew it, I guess people would just have to take his word for that, who knows. I’m sure we’ll hear more between now and April 2027.