We rode the bus a few times to MK and HS from POFQ last week and shared one time. We went at 2 pm to MK (not shared), at 8 am to HS (not shared), and returned at 10:30 am from HS (shared) and at 12 am from MK (not shared).
We also rode the bus home from Epcot (DH dropped us off) one night at 9 pm and that bus was not shared.