Yes, it would be. However, there are some issues with that idea which prevented it from being used in practice.
First, a given tile will have different cell types in the original maps, so there is no clear way to automatically assign the correct cell type. The tile group information would be helpful, and I had thoughts of manually adding that information, but as it's a manual process, I just never got around to it. Also, when a lot of the map editor code was written, cell types were perhaps partially forgotten about, and only really remembered after most of the tile pasting code was done. There is also the issue that since Outpost 2 can allow the two to be set independently, it's sort of nice to be able to do so. But yes, even in that case, a good default would have been nice.
Come to think of it, that VB project I posted a few days ago was probably what I was going to use to add the cell type information. But like I said in that post, the project was never really finished, and contains a bit of odds and ends from various tests and ideas that never quite led to the original idea.