Well, Scott,
It seems, you're kind of asking two different things. Your subject asks how many gas coaches have 50 amp service. Then, read into your post more, sounds like you're really asking about how many come with inverter/charger systems and upgraded coach batteries. Two different questions, with very different answers there. :)
If you're asking for percentages of gas coaches that come with 50 amp service...I'd say a LOT. Probably ALL, when you get over 32' and more than one air conditioner. Only snmaller MHs with a single Air cond. unit would be wired with 30 amp. Everything else, regardless of gas or diesel, is almost certainly going to be 50 amp.
Now, if you're looking for percentages of gas coaches that come from the factory with an inverter/charger and upgraded coach batteries to run things off A/C with the inverter, that is probably quite a bit less with gas coaches. It seems to be getting more and more popular in recent years, though, with all coaches (gas and diesel) moving to residential refreigerators from the factory.
