Maybe you're out of date. There's certainly more than 2 or 3.
The biggest gap of the arterials is Dundas. I imagine we might be holding off because of Dundas BRT which calls for cycle track/MUPs. Mavis and Cawthra also are notable gaps. Other big issues are highway crossings for 401, 403 and QEW.
For what it's worth, I have a 25km circuit that is about 80-90% on MUP, off street paths, or cycle track. The rest is on low volume residential streets.
In addition to the Argentia cycle tracks NL pointed out (I can report they are substantially complete), a 4 to 2/3 road diet of Aquitaine in Meadowvale, including flexipost protected bike lanes, was recently completed.
I have to say, I think Mississauga does as good or better job of creating a quality cycling infrastructure network than the suburban parts of Toronto.