I'd say, more tolerated. Because they're the devs, the lemmy.ml instance is considered the flagship instance.
Where new features go live first, a number of official support communities are and because it was the first, the perception that they have some of the biggest comms
The rest of the Tankie Triad (Grad and hex) don't have that so that's why they're pretty much widely defederated from, it's a much easier decision.
I say perception, because the comms there are only the "biggest" by subscriber count. If you look at the statistics by monthly active users, it tells a much different story where only a single .ml comm breaks the top 15 comms Lemmy-verse wide
Ah, it's possible, but unlikely thanks to its open source nature
It has been suspected though that .ml is running a slightly customized version to help hide their censorship, but I have only read of accounts of it happening to others and no direct evidence