Just be certain the sleeve meets the minimum size dictated by the show - it is 4 inches for our show. I was in charge of hanging the Junior's quilts and 2 of them did have sleeves but there was no way we were getting a dowel through those sleeves. We ended up using safety pins to create a sleeve by rolling over the top border of the quilt. Both quilts were huge. I explained what we did to the juniors and their grandmother and they were happy that it worked out and that their quilts were shown.
This is not something we could or would do for an adult's quilt. One quilt slipped by take-in without a sleeve, so one of the folks at judging contacted the quilter and arranged to get the quilt back to her for the sleeve and then collect it to get it hung the following morning. Our guild offers a "finishing" meeting where various sleeve/binding/finishing techniques are taught the month before the show.
Cheers, K