Hello! Thanks for reading and for the question!
Hahaha, I’ve seen that stated around online too. Honestly, the only reason you wouldn’t use these or any other pair of headphones for mastering work?
A lot of folks insist that the only proper tool for mastering audio is a pair of balanced studio monitor speakers.
Of course studio monitors, even expensive ones, have trouble hitting the lowest sub-bass notes the way that even cheaper headphones can…so depending on the genre, they might not bring out the notes you need to hear. And more and more audio is mastered by people who aren’t working in multi-thousand dollar mixing studios that are tone balanced and corrected. Are you really supposed to try and make your bedroom/office mirror the speaker setups used by record companies?
No. No you aren’t.
The old adage was that you should master on speakers because most listeners would use speakers…but these days, most music/movie/game consumers, at least in my experience…are using headphones attached to a phone or a console. The days of the mass audience sitting down in front of a nice home setup to listen to music are starting to fade into the distance, relatively speaking.
So go ahead and master on these or any other relatively balanced headphones you’d like to use. No one will hate you for it except the most picky of internet people. The Sony’s are close enough to neutral that you won’t be totally destroying your sound when it’s played back on other systems…and you could go crazy worrying too much about this anyway.