Given that the console has more than 2 times the RAM available to games when compared to the PS360, long loading screens makes no sense to me.
I believe that this problem is an evidence that the the Wii U version of the game is just a simple port (and I don't blame them for that because unfortunately the Wii U version is not going to sell a lot).
While developing a game developers usually have can use the RAM memory to improve the performance in two main ways:
1) Prefetching -> load the next stage of the game before while the player is still playing the current one (quite simple to implement and test). They could easy do this on the Wii U version but it seems that they do not have the resources;
2) Algorithms adaptation -> trade off RAM memory for performance by using things likes Caches, Hashtables or other memory greedy data structures (takes a lot time code and test);
