Like storyline wise? In the artwork there were four files one was of the Baxter Building, A Space-Station, A Kree Warship and a Normandy Flashback.
I was always interested in what was to come.
Perhaps originally they were planning specific missions to unlock the fourth costume. Like how Cap's 4th was his WWII outfit, so maybe his level would have been on a Normandy map.
I'm guessing the other three were all part of a different story path with the Kree attacking and you had to go fight them off, which just seems like overkill with the whole Doom has Odin's power threat. So that was probably thrown out earlier.
Anything that says anything more about those at all?