Does Apple ever announce anything before the day it happens? This is the company that drops iOS, macOS, and M1 on developers the day they do the public.

I'm not sure where people are pulling all these Apple silicon timelines from, but I can guess :)

There’s not been leaks, but there’s no reason to believe that it won’t be coming any time soon. Hypothetically the latest it would come out is in first half of 2022, but I’d be surprised if it took that long for the 16 inch macbook pro.