I have three M1 Studios: 2 Ultras and one Max. One of the two Ultras has the coil whine. It's NOT fan noise. It's also intermittent, and only audible in very quiet room. The solution for me was swap it to a room at the office where there's so much ambient noise it can't be heard. I also just got an M2 Ultra Studio yesterday, no whine at all.
Bottom line, contrary to rumors you see online, it's an intermittent noise and only seems to be present on some Studios, not all of them. Not sure if that will carry through to the M2 version. As I recall some teardowns showed that there were two different power supply designs/providers on the original Studio and I've wondered if only one of those was susceptible to the coil whine issue, hence the fact that it only shows up on some Studios and not others.