I think the O/P might be referring to lack of OPP traffic. I'm looking at Whitby and there are 3 T/Gs patched together right now.
MTO group 3904 is the master for both Toronto and Whitby OPP so he may not be hearing anything based on whatever T/G he's trying to monitor. Otherwise Mike you're right, Oshawa CACC both north and south and Toronto CACC are all there.
If you're trying to pick out Whitby OPP specifically (5K), they now have 5F callsigns - the detachment merged with Toronto. Orillia and Barrie (1M and 1B) are now one as well (1M).