I think adding trucks to waze is fine - lot of them on roads (also at night). But I think there should be then a second separate drop-down menu, or an "on/off" button in the future in WME, as a parameter for a segment, to set separate conditions for routing, based on profile(?) chosen - could be applied to HOV lanes as well maybe. And then it would require also specification of truck-restriction for that segment (speed, driveable height, turn restriction, overtaking restriction, weight, dangerous load, etc.)
And so far I still say NO to bicycles, pedestrians. The usual GPS modules in phones in big cities IMHO can't fix your position with such a precision, that waze could for 100% distinguish whether you are on the road or pedestrian boardwalk which is right next to it. (plus imagine the fun with tons of segments with mixed driveability and weird routing during mapdate days - I hope many of us here already experienced and know what I'm talking about)
As somebody mentioned here emergency cars - their data would mess up the data from the jam created by "private cars" (if it all won't be profile-based). Honestly, for emergency vehicles drivers waze can only be a navigation app., they don't profit from other benefits, as they "can ignore" jams, red lights, police traps

. And I don't believe they'll be reporting something during an emergency drive to an accident (which will be already reported by other wazers anyway

).
(Country is in my info

)