It’s by no means unusual for ATC to hold our heli on the runway prior to departure, in CAVOK conditions, for a preceding fixed wing departure in a strong “away” crosswind; even though it’s perfectly obvious from the adjacent windsock that wake turbulence from that aircraft was never really over the runway and well within three minutes it wouldn’t even be over the airfield.
Thing is, when hover taxiing (or arguably, partly so, even when ground taxiing), a helicopter has already taken off to get to the runway departure point. To subsequently hold it for wake turbulence reasons is absurd.