It's only been a couple of days, we'll get more data journalists breaking it down better soon.
You know what would be really helpful? If the algorithm was released to be publicly reviewed. Oh, but the government is refusing to do that, and Ofqual made anyone consulting on this project sign a 5 year NDA or they couldn't get involved. Hmm.
Edit: and while I'm pretty sure the data will show schools weren't on track for that inflation, actually no I disagree with you that it would be fair to extrapolate previous cohort improvements to this year's anyway.