What does Rewind Story actually do?

Question

I went through the campaign on Veteran and finished everything except the Strike Force missions.

I want to go back to the beginning and finish up the challenges I missed and do the Strike Force missions on a lower difficulty.

Does rewinding the story back to the first mission reset challenges/intel? Once I rewind the story, can I lower the difficulty?

I know New Story clears out everything, but how does Rewind Story (to the first mission) differ?

Answer 1

No, your challenges and intel will not reset. From what I have observed changing the difficulty does not affect intel either. In otherwords, if you're having trouble getting at it, play it in the lower difficulty.

One quick note however. If you are replaying missions in attempt to gain some of the "missable" achievements (ie. You must make specific decisions across various successive missions etc) then you must use the "Continue Story" option rather than "Mission Select" when progressing past the starting point of your rewind.

Answer 2

You only lose some gun skins. I found out the hard way.