The need gets less when one has ‘calibrated’ one’s hearing over time. Of course, it pays to periodically ‘verify’ that one is still on track.
I don’t know if it is still done this way, but studios would tend to ‘standardise’ on particular makes/models of speakers that many mix engineers were used to, so that they didn’t need to spend time ‘re-calibrating their ears’, thus saving time and money.
If I were working with a new genre, I would be going through the multi-environment testing phase again, because the timbres may be different, and one must be sure one is ready for that.