why change the rules ? if i remember correctly it was the democrats that wanted the mic mute rule in the first place.
The Harris campaign said in a statement to the BBC's US partner CBS News that it wanted both candidates’ microphones to be live throughout the full broadcast.
The Trump campaign reportedly wants the ABC debate, scheduled for 10 September, to be governed by the same rules agreed when Joe Biden was the Democratic candidate. That would mean the microphones being muted.
https://www.bbc.com/news/articles/c5ylj0qg2rwo