Just suppose ATC has a heavy in landing configuration coming up behind you, to pass safely clear above, but he is worried that the wing vortices may be strong enough to flip you upside down?
I have experienced such strong vortices, fortunately, we were flying across, and experienced violent up, then down. Both off us had seat belts normal snug, and hit the overhead hard on the downer.
Cessna 150 with another pilot flying first time, second time, Piper 182, clear air all around us, we never saw the aircraft that produced the vortices, but noticed that we were in line with a major runway at an air carrier airport.
An outbound at full gross, and climbing rapidly produces strong vortices, and most likely produced the second event.
In all my years of flying, I cannot recall ATC reaching out to me for a trivial reason.