Unlikely, the vast majority of MIDI cables will only be wired to the Central three Pins, but you’ll see from this that DinSync utilises the central and outermost Pins - a few MIDI cables could be fully wired (all pins connected) but it’s not likely that you’d have one of those
Pre MIDI (early 80s) would be the right ballpark, but gear made after this is of course free to use the older analog standard