^
It seems unlikely.
Are you riding a $5000 road bike around? That might change things if high-end bike theft is rampant in your area.
What I mean is, that for the above to be plausible, someone would have to be casing you and your bike. Watch you go to work/school everyday, see that you are using this particular lock, and deem it worth tampering with your 'at work' lock that you leave on the rack. I really don't know of anything that they could do to it that would help them steal your bike more quickly. Not anything that you wouldn't notice anyway, like.....cutting part of the way through it(?).
Again, it seems unlikely to me.

All that said, I don't recommend leaving a lock on a rack to use daily. Why be predictable?