I don’t see paying for some sort of way to cut down on waiting in line as creating a class system, anymore than offering deluxe vs value resorts, free busses vs private Minnie vans, quick service vs signature restaurants would. In your post you mention being treated better the more you pay. I agree, all guests should be treated respectfully and thoughtfully whatever they paid to be there.
But I see this new idea as just another add on that you can opt to pay for or opt out of to budget better. I think some people may balk because it feels like something that was free that you must now pay for, but it sounds like a new product to me.
And in general, I think a Disney vacation is something that, if you’re able to afford it, already puts you in a privileged group, even if you plan a very budget conscious trip. For some families, even the cheapest Disney visit is out of the budget. An argument could be made that a Disney vacation is already feeding into a class system, it’s just a matter of personal perspective.