According to Michael Roback :

... When I
moved it I merely unscrewed the box from the stud and pushed it up about
1-2" and then refastened it. I did not undo the box connector and pull the
romex through. In order to move it this way, I had to push the romex into
the middle of the stud bay and kind of bend it around a bit. In other words
I couldn't just push the romex up and keep it straight. I guess it was
stapled to the stud somewhere above. I am wondering if this added bit of
pressure on the box/connector is in any way a problem.

Exceedingly unlikely to be a problem.

Inspectors don't like seeing the wire "tight" - there should always be a bit
of slack - many electricians leave an inch or more of slack. In some cases,
you'll see a lot more than an inch... I usually leave a couple inches.

By "pushing" on the cable, you formed (or enlarged) a bit of a loop between
the box and the nearest cable clamp (or hole in the stud). Unless you had to
wrench _really_ hard at the cable to bend it (ie: a cable staple was _very_
close), there won't be any problem whatsoever. Most times there's about
4-8" between the box and the nearest staple. Plenty of room for giving
a bit of a push without hurting the cable.

That being said, if the wire is real old (ie: the 40's), the insulation
can sometimes be rather fragile. If the stuff didn't come apart in your
hands, it's fine.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.