Ok, here is the final, hard won truth. I scienced this motor, because SCIENCE.
There are two small M4 set screws hidden deep within the blue epoxy filling both holes in the can. The shaft has two unthreaded cavities to align with those set screws.
If you’re going to replace a shaft in the latest gen Flipsky motors, I recommend drilling both holes out with a 7/64" (or 3mm) drill bit. There’s the outer plug, a gap, and then an interior plug on top of the set screw. You’ll know when you’ve hit the set screw - be gentle. Should take a 2mm hex key. You may have to dig out chunks of epoxy to get the hex key to bite.
Or, you can be like me and put the entire can under a hydraulic press.
Don’t be like me.
Now… after I check this steel shaft for straightness (which it most likely is still perfectly good), should I fill the aluminum can shaft hole with JBWeld and use a drill press to create a new, tighter mounting hole? Or see what high strength retaining compound can do instead?