Okay, so by the time of Tomorrow is Yesterday, time travel is a known, if not understood, thing in Star Trek. My personal theory is that after that point, Starfleet started making sure that all of its technology was as backwards compatible as possible, so if you got stuck back or forward in time, all your gear would still pretty much work.
Like, there’s at least an adapter to connect this:
…into this:
and share data. In fact, there could be some kind of hardware or software solution that filters any information that could contaminate the timeline.












