I've never heard that!
Coax length in your application is not important. All VHF airband antennas work with any reasonable length of coax.
22" is ? of a wavelength at approx. 134 MHz. Unless you were making your own antenna, it's a useless number... a little shorter than what I would use for an aviation antenna, and a little long for the two-meter ham band. Might be a reasonable compromise for both, though.
Coax cables cut to multiples of ? wavelength, however, can be useful for measurement purposes, but must take into account the 'velocity factor' of the particular coax cable used. The velocity factor can physically shorten the coax length by more than 30%. Without further calculation, such a cable is only useful in a very narrow frequency range.
Use as much cable as you need. I'd do the same as Kent and leave some extra for servicing. No harm there.