I think you are wrong. When my bearing unglued itself alone, I noticed some play in my front bearing and a strange noise of vibration, like the bearing moving in the housing.
Then I opened my motor and glued again the bearing in the endbell ==> no more play of the bearing in the housing, and no more strange noise, the motor just rotated quiet.
==> I think that if the bearing is not glued, it use prematuraly the housing, no matter the rotor shimming.
Inferno VE MMv3 NEU-CC 1515/1Y 4S "Flying machine"