Yes, this is probably the most important reason for closed door depositions.
https://www.washingtonpost.com/us-policy/2019/11/14/career-white-house-budget-official-expected-break-ranks-testify-impeachment-inquiry/
This will be a close hearing tomorrow. I'm not sure why unless Sandy is worried about witness intimidation. But things are moving along.
The main reason is that the DOJ refuses to help with the investigation part. Accusations of crimes prompt investigations to see if there's any evidence to base any potential charges on, or in this case, to base impeachment on. There are numerous good reasons for investigators to keep their investigations out of the public eye until they get the information and evidence that they need, and since the DOJ wouldn't help, Congress has had to do the investigation themselves. That's the reason for closed door hearings first. They don't know if the witness is going to give them information that should be protected or if the witness even has any useful information at all, or information that would lead to other witnesses being called.
Republicans damn well know this. They are mostly lawyers themselves. They pretend to not know the nature of investigation as opposed to hearings and trials that come *after* the investigation phase. I'm still not sure what is the payoff for them, what they have traded their conscience and careers and reputations for, or if it's worth it, but they've traded their integrity for something. I can't imagine what would be worth all that for them.
It is gratifying to see how much more difficult it is in these circumstances, vs. during the Mueller investigation, for Republicans to turn it into their usual clown show of conspiracy theorism and character assassination. IMHO, they are falling relatively flat... which probably means that public sentiment toward conviction will likely inch up some fraction of a percent over coming weeks.
That part is depressing. But I am also grateful for the sheer volume of facts that are being read into the public record in this case. Even if the current Senate fails to fulfill its duty, history will record their cowardice in no uncertain terms.
Even I am surprised at the weak ass defense arguments from Republicans, and I was expecting weak argumentation. I think we all were. That counsel ... dude, I was beginning to think he was working for Dems. (Side note: Under House rules, can Repubs replace that counsel? I'm curious because if I were a Republican, I would sure as hell want to. And I'm not suggesting he's a bad counsel, just that he seems too decent and honest to do what Republicans would want him to do, to obfuscate and badger, in other words.)
As for facts on display, I've always believed that this was the most important reason for the hearings - laying out the facts, hearing the testimony in a setting that even Republicans can't stop or distort, much less Fox talking heads. They can whine and lie after the fact, but they can't stop anyone from hearing the testimony as it happens.