I'm pretty sure I remember the Voyager being displaced into the Delta Quadrant before the Equinox as didn't Janeway state in an early episode that there weren't any other Federation ships missing? But I think it is made clear in the two part episode that the Equinox has been lost for much longer in the Expanse? Strange that both ships made different enemies by different decisions.
JB
Janeway did say in "STATE OF FLUX" that there were no missing ships to her knowledge. But Equinox was definitely taken by the Caretaker first. How long before, we don't know.