I just checked Google to see if I'm mistaken but even the Wikipedia page on wind turbine design uses it:
"For a given survivable wind speed, the mass of a turbine is approximately proportional to the cube of its blade-length."
So I'm not sure why you've never heard that term but it definitely is in use.
Afaik modern turbines are specified to reliably withstand an "extreme 50 year gust" estimated by their locales "Wind Class"  Some headroom is likely as with all large constuctions, building, bridges.. The matter of what stronger gust speeds might be survivable by the majority of installations is not specified.
Also with offshore windfarms, the big extra expense is in installing the towers and cabling. They are getting significant subsidy to be built for 15 year power purchase contracts, but once those towers and cables are built the farm can remain very valuable at the end of the contract, if refurbishment is required it could be remarkably cheap especially with a fleet of specialized ships to it carry out, some of which are already at work putting them up.