These BLM types are taking advantage of white guilt to do these sorts of interruptions, and the organizers are cowards to stand up to these bullies. Peaceful protests are legal. Protests that disturb the peace are illegal, and the protestors should leave or be arrested. Full stop. You can't hijack and keep hostage a parade for your protest.
I think the organizers did the right thing. These folks would just try and take over on the day like they did last year. The organizers just cut that forum out from underneath them. Now they might understand blackmail isn't going to work, it will just
**** off all those who enjoy these festivals and turn the general public against them. Hopefully this year is a one off and people will be more reasonable in future.