I absolutely agree. When people said they wanted a D/P remake, they were probably meaning that they wanted something that rebuilt the region from scratch; for example, the environments all being updated and playing similarly to Sun and Moon, albeit far less linear, and the character models being upscaled.
I'm sure they didn't mean "just D/P but with 3D models."
If Square Enix is able to remake their games like this:
https://youtube.com/watch?v=HeTBgDpnEI4Then TPC and Game Freak should have no issue achieving a similar result.