If it was me I would take it in and expect them to fit a new final drive. The seals normally go when the bearings go.
If they ask for payment I would tell them that it is less than two years old, which they will know, and it is still under warranty with BMW. If they have a problem they need to take it up with BMW.
My 2 year warranty expires next month and I noticed that the paint is bubbling on the final drive. Took it to the local dealer, where I didn't buy the bike from and they took photos of number plate, odometer and final drive. I'm waiting for a call for me to take it in for a new final drive, after BMW has given the go ahead.