I'm sure it was done in coordination with the advertisers that pulled their ads. Probably a group coordination between the companies and groups like the Anti-Defamation League, the NAACP, Sleeping Giants, Color of Change, Free Press and Common Sense that spearheaded the original advertising blackout.
I was on ChapoTrapHouse a day before the ban. It was indeed leaked, and the ban happened exactly at the same time that it was leaked. This probably wouldn't have been the case unless it was coordinated.