That article is, as you can imagine, all over the RV boards. As a potential (but by no means definite) RV upgrader in a year or two, we had all but abandoned the idea because of the cost of gas. However, at current levels the price savings upon purchase of a new or new-ish class A gasoline RV is thousands lower than it was, as in $10K lower or even more. For diesels, the savings are in the 10s of thousands.
That's 2500 gallons of $4/g gas which at 7 mpg means 17,500 miles. Most RVs are driven under 10k per year. So arithmetically, the savings probably more than offset the newly expensive gas cost for the average buyer.
Obviously there's more to the decision than fuel, but there are the numbers.