Rode GFT with my nieces the other day and they LOVED Coco, and didn't get much out of the existing GFT. Personally, I love GFT, especially since they added the MMR animatronic at the end, but there is something to be said about keeping things relevant for the new generations. If they're going to fill EPCOT with IPs, at least Coco is a good one and would actually fit the pavilion.
BTW- the nieces new all about the stuff on display in the lobby of the Mexico Pavilion and that's how they told me all about Coco and how much they loved it.