https://www.ontario.ca/laws/regulation/900611
Specifically, schedule 6
https://www.ontario.ca/laws/regulation/900611#BK8
See sections:
1. (1) (a) my interpretation note: If there was a mudguard originally installed, it has to have one per this requirement - but it doesn't necessarily have to be the original one. Fender eliminator kits should fail this.
6. (1) (c) my interpretation note: The problem is the word "prescribed". Prescribed by what? If it's prescribed by HTA then I will grant the point because the HTA doesn't require turn signals on motorcycles and it's silent on requiring reflectors (any of them). If it's prescribed by "as installed by original manufacturer" then everything originally installed has to still be there and work (or be replaced by substitutes that are equally functional). If it's prescribed by CMVSS 108 then same situation.
Having said that, I think you will have a hard time finding a mechanic who would pass a motorcycle built since the 1970s if it doesn't have functional turn signals. It doesn't matter in this particular case, because obviously the original turn signals are still there. The problem is the lack of the mudguard or any equivalent substitute ... It's the very first line item in the inspection requirements ...