Private Stake should never be forked regardless of the situation. The only legit reason is if the private stake owner agrees to it.
I cant be 100% certain but I think that is the total consensus of witnesses. But obviously they also wanted to protect the chain. Think about this justin could have done some incredibly bad stuff when he had all 20 block producers... like really destroyed everything. It's not a matter if we think he would have it's just bad that one person could have. And at the time there was lots of talk of token swaps moving over to tron. Etc