Update: I went to Yamaha's US and EU sites and downloaded Owner's Manuals for 2020 and 2022 MT-09s from both sites. Interestingly, the maintenance intervals on both generations differ between Europe and the US. In Europe, the intervals on both generations are 6,000 miles, while they are 4,000 miles in the US.
I suppose, because I'd have to deal with Yamaha US if I ever had a warranty claim, I'll follow the US intervals.