Ok, ok, so the chapters with Wagatsuma getting beat down and traveling back to the "present" were in the previous timeline before Gaku got here. Gaku's presence has just created its most obvious distinction from the "past" timeline yet, with Wagatsuma finding out he wasn't betrayed and staying. I can't imagine how much of an impact this will have...
Oh, and he just accidentally outed himself as a time traveler to his fellow time traveler. This should be GOOD.