Yes, the nominal length is overall for an Escape.
The most common practice in the industry is to identify all forms of trailers (box and flat deck cargo, travel trailers, whatever) by the length of the box, deck, or body, and the model names usually reflect that. The overall length (longer by the length of the tongue) is given as a specification. Most moulded fiberglass travel trailers and some others are different - the model names indicate the overall length instead, which often causes confusion.
Fifth-wheels are fundamentally no different from conventional trailers in this repect. The pin is usually around the front wall of the body, so the body length and overall length are similar, but the pin is routinely a bit forward of the body (and the bumper sticks out the back), so the body length and overall length are different - ETI just seems to think that buyers won't be concerned with both specifications.