Likely yes, but completely meaningless, as the highlighted word explains.
Unloaded doesn't take into account aero drag, wheel slip, even the drivetrain losses are going to be different compared to loaded.
Also, your max rpm doesn't mean too much, apart from telling what your top speed is... you really want to be looking at how the rpm varies around the corners to get the boost set right... then set the turbo.

(and as syctherat and Benzhah have said, testing a motor unloaded is a sure fire way to making to stop suddenly as the rotor falls apart...)

Regards
Ed