The original comment referenced the U.K., where it is definitely not required, but is becoming more common.

I am surprised at the idea that MVHRs have been required anywhere for as much as 20 years.

Where you are makes a big difference. 20 years ago I read about some 'passive house', and realized it was actually less insulated than the codes in Minnesota require - but it was in a mild climate so it was passive, while the more efficient houses in MN are not passive.