When i've been in to Shoreham then my final call (at 500 feet or so) has always been acknowledged with something along the lines of "G-CD, continue approach". That's fine. Actual clearance can come quite late, I agree.
It's just "G-CD, standby" or no response at all that make me start to think about what to do next. Had both at an ATC airfield, but both times clearance came in time to avoid the go around.