I think it depends on schools but most of them may. They just won't review your file until it has MCAT scores. If they use MCAT as one of their screening factors, you wouldn't recieve them until your MCAT scores are in.
Like everyone said, it just depends on the school. I have about 20 unfinished secondaries sitting on my desk and I haven't taken the mcat. All the osteo schools I applied to didn't screen. A majority of the allos didn't either. A good source of income for a lot of medical schools. good luck