From an advisor side I believe it is acceptable, and that with different approaches it is possible to leverage technology to replicate a similar result. If I were a buyer in a transaction that was going to bring across people/ talent/ key performers, I may be more hesitant to sign without having met face to face, given that cultural clash is such a significant underlying reason for failed mergers. This may be even more important in higher context cultures where communication is more nuanced.
I agree with other comments above that in some transactions the value being acquired is very tangible or quantifiable and in such a situation virtual DD is just as acceptable.
