It's iffy. I remember the initial reports of cheering, they were all over the place. But that's conspiracy theory territory... the official story is that it didn't happen.
Trump tends to drop these CTer hints, from CT sources, into his speeches. Then he cites "seeing them on TV" when in reality, the places these things showed up was youtube CTer documentaries.
Ari Fleischer , former White House press secretary during the Bush administration, told CNN that Trump sounds like a "truther". He's right. Trump spent a lifetime creating buildings. Trump is a CTer on the birther issue, one with far fewer supporters/evidence than the 911 CTs.
Imagine if Trump was a 911 truther. This is the 2nd time he's done it. The first time he blamed "the buildings coming down" during Bush's presidency. Not "we were attacked" - just "buildings coming down". THAT IS TRUTHER TALK. Maybe that's why he has the GOP base so scared. I've long moved on from paying attention to 911 CTs. It was interesting, but it's history now. I haven't been to the CT board in a year or two lol.
Imagine a truther winning the GOp nomination lol. too funny.