I see you used two circles from draft to make the sweep, but I can't see how you got your orientation to make the draft circle on the revolution. Honestly I didn't even know circles could be used that way directly from draft, but I'm stymied on how you found the proper orientation.
Oh, that's easy.
First I created the revolution in Part Design. then I switched to Draft Workbench because I find it a lot easier to use for these types of operations than Sketches are. (maybe it's just me?). First In top view with Working plane set to Top I created a circle that was snapped to the midpoint of the outer seam of the Revolution. Didn't matter what the radius was, as that can be changed later on. Then I selected the end face of the Revolution and clicked on the Working plane to set it to that face. Then just center snapped a Circle to that face and snapped the radius to the outer seam. Now I have a circle the same radius as the radius of the Revolution. Then I used Placement and rotated that circle into position on the Z axis. Then it was a simple matter of Sweeping Circle using Circle001 as the Path. Cut then done.
Yes, Draft objects are very useful for Sweeps, Lofts, Extrudes, ShapeBuilder, etc.. Once you figure out the Draft Workbench and all that it can be used for, you'll wonder how you ever got anything done without it.