Irrespective of the degree of swing, I do think there is risk that some folks might suffer mild motion sickness on the gondolas. We took a family ski trip to Breckenridge in late March. While there, we rode the BreckConnect Gondola up to Peak 8. There was no wind to speak of, but the gondola did sway as it was making its way through two turning stations. My 14 year old got little queasy on the ride due to the swaying motion of the gondola. It was nothing that ruined his day or anything like that, but it's something I was not expecting.
Side note: Disney vacations are expensive to be sure, but I am still reeling from the price of lift tickets! Also note that quick service meal prices at the top of a mountain might actually exceed those in the Disney parks. It was still a really fun trip, though.