The axle has bearing at each end of the stator, so it is well supported.
The end ?bell? is then attached to the end of the axle via a closely tolerenced hole maybe 15mm deep.
Then the outer shell is secured to the end ?bell?. This is usually just a press fit, but some motor glue, of screw it on.
So the weak point is probably how the shell attaches to the bell, as the tire force will create a cyclic moment that will try to wiggle the shell off of the bell.
But it hasn't been an issue for me yet. But I think I remember someone once having it come loose.
Motors with a skirt bearing will support the end of the shell, so there is hopefully less of a cyclic moment trying to work the shell off of the bell.
Here is a random pic that may help.