In terms of moving Speedway and Small World, there are very practical reasons for each.same people want to remove small world and cop and move to epcot remove speedway ROA and tom sawyer. They dont realize A this isnt roller coaster tycoon that its all point and click, and that we need to keep the feel of MK. MK has space and doesnt need to remove anything... there are still plots.. and lets be honest they could extend the berm and build another land inside the MK.. this isnt disneyland. Id bather spend billions extending the berm and building a villains land than spend that money removing the energy and classic disney feel from moving major rides and draining ROA
Small World creates a massive chokepoint and has a very unappealing facade (by far the worst in the world), and wouldn't be all that difficult to move as it's essentially just a massive warehouse. Additionally, there is precedent for this, at one point in time, it was planned to move IASW in Tokyo, inevitably, that plan fell through, but the move was far less needed than WDW's move.
WDW's Speedway is extremely ugly and creates an undesirable spot in the park. Speedway attractions have recently been disappearing across the world. Tokyo lost theirs for the BatB expansion and Hong Kong lost theirs for the Marvel E-Ticket expansion and Shanghai never had a Speedway. So relocating it to Epcot would be a way of saving it from its inevitable demise, while also giving families with young kids another reason to visit Epcot.