Based Takes
I believe Matt does. The question is why high profile deniers wont talk to someone who is an expert on the subject. Well we do know why really. They'd have no explanation for the historical record.
"High profile" means nothing, it's just an excuse to avoid debate. If the historical record "cannot be explained" (what can't Revisionists explain exactly? Revisionists have literally contended with everything from the "historical record") by revisionists, it hardly matters whether the revisionist contending with it is "high profile" or not. This unnecessary stipulation is a poor attempt at two things:
1.) to avoid debate because it's them who cannot explain the "historical record" and
2.) a way for them, like Ryan said, to engage in a low form debate which is intended to "humiliate" people they don't like, presumably to gain notoriety for themselves and to be able to posture their cause as "true" and their enemies as "wrong and dumb" without actually having to actually prove anything, let alone commit to any arguments they can't wiggle out of
In a stream you can commit the "Holocaust of the gaps" fallacy as much as you like and completely render any discussion to be pointless and drawn out. It's hard to make points and also recall in exact detail what your opponent has already said and then confront them on it later if they contradict themselves. Even if you manage to do this they can just deny it in the moment and it goes around and around in circles. It's a terrible format.
Seems to me these people are more interested in trying to insult people they disagree with and get clicks on it, rather than actually debate the point. This is because they don't have any respect for revisionists, they don't even take revisionism seriously. To them there is no debate, only people to humiliate. So the 'point' being the historically contentious issue of the Holocaust is actually not their main focus. This is why they won't debate, and probably also because they're scared of being humiliated themselves.
For all their talk of how "scared" and "unable to contend with the historical record" they claim revisionists are, they're not exactly eager to prove these assertions, which in itself says a lot.