I'm not aware that it changed. It depends on what airport you were flying in to, who the nearest primary airport was (if any), and if the tower had radar.
I know when I was in school, at BVI, under IFR conditions, it was one in and one out. Under VFR, we never had that problem, but then again, we usually never had more than 1 IFR on an approach at a time. We also had a CTRD as well, which gave us additional options.
The only other thing I could think of, is that the tower did have radar and it was INOP at the time, and then they had to revert to other techniques.