This is exciting, and I'm hopeful that this will accelerate her momentum. But I don't think we can count Trump out yet. If nothing else, he's usually good at playing to his base.
Harris has a lot of pressure on her. People are basically expecting a total domination from her, so anything less than that could derail her momentum very fast. And Trump might be terrible at classic debating, but he is actually very adept at bulldozing others by ignoring speaking in turns, deploying a fire hose of lies and misinformation and loudly talking over others.
Remember that Harris is an experienced prosecutor. Her literal job has been dealing with liars, cheats, and various scummy and desperate lawyers for years. If anyone can shut down the Trump oral vomit, it's going to be her.
She is, but Trump is special. I don't know that any previous experience will necessarily apply. In the courtroom she would have always been empowered by speaking from a position of authority - Trump will show her no such decorum.
That's on the moderation, and I can't say I've seen good moderation for the big debates in a long time. They should bring in a grade school teacher who does regular debate classes and let them do what they know how to do.
I guess I left that part unsaid, but yes. With good moderation Trump wouldn't be able to run his schtick - but here we are. We have to play the hand we're dealt.