What is the industry standard for the height from the ground of the fifth wheel coupler for North American commercial semi-trucks?

There isn't one. Vans have a lower fifth wheel height than flatbeds or tankers, and most trucks have a control to raise or lower the fifth wheel height by inflating or deflating the tractor's rear airbags.

The important spec is the top of the trailer, and that can't be more than 13'6" unless you have an oversize load permit.