I'm Canadian and hadn't heard about this. I thought all Residents were paid!
But I can see how they would protest to look good. Nursing and support service unions across the country are being offered 0% wage increases over three years, no COLA clauses, no retention packages and in some cases reduction of benefits. So if there is money for the Doctor side of the board, there should damn well be money for the rest of us.
My union has been offered 0% for two years and a possible relook for the third year. No extra benefits, "just a be grateful you've got jobs" attitude. My contract expired March 31, 2017. I'm not permitted to strike because I'm considered an essential service. I live in a province that has what you would consider a left wing, socialist government. There is also an unofficial hiring freeze on all provincial staff and hospital workers are basically provincial (think state) employees.