My experience is that Due Diligence before finalizing & announcing the deal is confidential and in most cases is done in a closed-door room. Frequent meetings beforehand with many employees/middle management may alarm the target company’s staff and may create an anxiety moment. So Virtual meetings & DD with the key personnel involved in the M&A work out best to avoid any presumed red flag among the employees. I agree, 100% of virtual meetings may not be as productive and build trust as they would have been in the case of in-person meetings.
As far as Cultural/ HR Soft DD is concerned, most of the Cultural DD is post-integration/post public announcement of the deal. The acquirer should during HR audit very well understand the overall cultural key points of the target company. There may be few cultural challenges however that won’t be a make or break situation. The Acquirer may have to adopt some of the target practices or eventually change/modify its practice. Nothing 100% can be achieved even in face-to-face interactions. It’s an evolving process till both sides settle down.