Anybody else have transmission/differential whine?

I've got 26k miles on my 2023 6MT. It developed a whine about 2000 miles ago. I haven't changed any transmission mounts or anything like that. I originally thought it was my exhaust that was vibrating but I had that fixed up and still had the noise. I hear the noise mostly in cruise. It's a constant whine that changes pitch when you get on and off the gas. It sounds very similar to the rear differential noise I've had on a couple of older cars with over 100k miles. It seemed normal for those cars to have some wear on the bearings but it doesn't seem normal at 26k miles. I took it to the dealer yesterday and they said the sound was coming from the transmission. I was hoping it would be a driveshaft bearing which would have been an easier fix. They will have to tear the transmission apart to further diagnose. I'm not totally sure if they will warrantee it since I have a tune. If SOA comes back and says they won't warranty I'm thinking I will keep driving it like it is. Maybe I'll change the fluid to see if that will help. If feel like it could be a benign but annoying issue.