At a slow enough rotation, the sealant will continually flow to the bottom of the tire. At a fast enough rotation, centrifugal/centripetal force will create a radial pseudo-gravitational force that will distribute the liquid evenly all around, and I imagine it will remain relatively stationary (relative to the rotating frame of reference of the tire), except for bumps. In between, other stuff happens. In particular, accelerating from a stop, there will be some lag as the fluid is dragged up from its pool on the bottom and flung out to the tire. The physical force that makes that happen doesn't come from nowhere, it comes from your legs. But it is probably imperceptible.