I agree, I would rather something new and they just re-do that whole part of Epcot.
I think Disney and Universal realize the big money is in Merch and that they get more money for rides that are tied to IPs. I said this before, but HP changed everything. Both parks are now going to do IP rides instead of original rides. I don't think it is that Disney can't make an original ride, I think it is they don't WANT to make an original ride. They get more money out of rides with IPs and they get bigger boast in attendance. I can't blame either company for taking advantage of this new way of doing things. The more successful these projects are when it comes to Merch the more rides we will get. If WDW sees an increase in attendance and spending increases for a ride they are going to want to do that more often.
I personally don't care if the original theme of Epcot goes away. I want the World Showcase, The land, and the Sea to stay. But everything else is just a shell of its former self. Disney won't make enough money off of opening a non-IP themed attraction based on science and so if they try to do that and it fails, Epcot sits another 10 years the way it is today. I would much rather an IP used, it be a success and more of Epcot is fixed. Just like if Frozen success means more rides for the countries even if an IP is involved, I am all for that.
Again, I don't think GoTG will be coming to any part of Disney, but replacing Energy with an IP, I am all for that if it means a brand new attraction.