Nope, Alexander Choi didn't disclose anything to the scammers during the call, Alexander is somewhat experienced in the industry, so he didn't do that. I have read from a few sources about this case and this is a very sophisticated scam, i believe the scammers are exploiting some form of vulnerability in video conferencing apps/platforms.

The scammers host the meeting and forward the link to their potential victims, i think that is where the scam happens. There is not so much information on what the malware is right now and what vulberability they are exploiting. But don't keep a huge amount of assets in a hot wallet like Alex did, and if you are not the host of a meeting in any of these third party apps, then you have to ne suspicious of it, be careful, there might just be a malware lurking in there.