I think there must be a lot of propshafts that don't get greased, particularly those with the NVH kit fitted as access to the grease nipples is worse and requires the tunnel panel removal. With the shaft being almost straight and no movement of either end the bearings don't move much, brinelling being more of a problem I expect? I have not heard on any UJ bearing failure, there must have been some as just about everything else has failed on the M3W, apart from the Mazda gearbox 😁.
