Remember, worms don't eat the stuff we put in they eat the tiny creatures that eat the stuff. I don't know if they would do ok or not, it would depend on the bin life that springs up. I assume the bin would have to be set up for a while to get biological action going. I have two bins that get nothing but cardboard and they do great. I have others that get kitchen scraps and lots of other stuff, like leaves and grass clippings. I see no basic difference in consumption rate after the bins have been setup a couple of months. Do a search on 'coffee grounds' as there is a wide variety of opinions on this subject.

in my experience worms aren't too keen on grounds, and the grounds tend to dry out too much too fast - the only way I got worms to [seem to] consume grounds is when I mixed them about half with carrot pulp from a juice bar, and I think it was really the carrot that got the microbes working well

Bill