I didn't notice this - perhaps because I am used to it - but this is historically correct. Bh and mh were different. Bh was made with both lips /β/ (like a b but letting the air out) so it could sound like /bv/. It is the sound used in Spanish for both b and v. It is reassuring to hear that this phoneme is alive and kicking.
Mh was different. It was /ṽ/ which sounds like a /v/ while holding your nose.