That doesn't seem right to me. My 2022 22MLE had a slide topper, and our 2023 23LDE with similar slide has one. Both were dealer installed. Looking at the pictures of a 2024 vs 2022, they appear to have similar distance above the slide out.
Maybe check with a different installer. There only needs to be enough room for a rail to be mounted under the gutter with enough tilt that the water will run off the topper. Mine is covered right now otherwise I would measure the distance between the bottom of the gutter to the top of the slide so you could compare. But maybe you could ask the dealership to compare for you? They sure look the same to me in pictures. Also, maybe ask specifically what the problem is?