Although Ford has been using the Michelin LTX M/S 2 (and before that the LTX M/S) as original equipment on the RV-package for the E-450, Michelin has never marketed the LTX tire line as RV tires. That does not mean it is unsuitable for that use. It just means Michelin prefers to recommend commercial tire lines, or the specialty X-RV tire, for motorhome applications. There is not really any such thing as a RV "rating" for tires. Most manufacturers do not make application recommendations.
The LTX M/S, in 225/70R16 load range E was "beefed up" over other Michelin LTX models by adding a second body ply. I don't know if that continued on to the LTX M/S 2.
"Light truck" for the tire marketing sense (and EPA emissions standards) ends somewhere around 10,000 pounds.