Control is not that clear to me either. Like was it bad in the present and only got worse via the thing (itself?) from the future?
Really doesn't matter to me.
I found that everyone going with Burnham really kinda sapped the poignancy of the moment. From one person bravely doing what needed doing to "gosh, the whole gang." Meh. In past iterations of this overused trope (that's redundant, eh?) it was beneficial to have a team along to help. This ep, for a few moments, seemed to say Burnham-suit-and Disco would have worked with just those three elements. Am I wrong? Does she need all the buddies? Sure seemed like a S3 set-up without a real reason, as others have noted.
Also, once again, there is no sense of urgency. There's S31 ships coming NOW, but we're gonna go to our cabins and pick mementos? Or have that meaningful talk about our relationship? Or record goodbyes? Move, people!