Yeah, it's called Hydro because in BC, Quebec and Newfoundland/Labrador most of the electricity is Hydroelectric. Alberta and Saskatchewan use primarily coal. Ontario is the only province that uses primarily Nuclear, Hydroelectic and Natural Gas, but their power distribution network is called Hydro One.
There are only 14 coal plants in Canada. 7 of them are in Alberta. 3 in Saskatchewan, 2 in Nova Scotia and New Brunswick has one of everything.
So shutting down the coal plants mostly impacts Alberta, and the fun fact is that Alberta can pretty much "mooch" off BC while it transitions to something else.
I am most familiar with the plants in Nova Scotia, so I will comment on those. Nova Scotia is essentially an island by both geography and the current grid. There is a HV line to New Brunswick, but capacity is only around 350MW. Nova Scotia does also have a line to Newfoundland but this is an underwater line of limited capacity also. Wind is not a reliable option, and utility-scale solar has issues due to the high latitude and punishing winters.
The power station at Lingan is ancient in terms of design, but the 4 units there have a capacity of 600MW (150MW ea). The outlook for this station has been bleak for many years and 2 of the units are already on a retirement schedule. The station at Point Aconi is much newer but capacity is only around 200MW if I recall correctly. The major issue for both is that the economy of Sydney (ex-mining town) is already very poor. Closing either, or both of these stations would be very detrimental to an area that already has serious economic and drug abuse problems. Conversion to natural gas firing is unlikely, the infrastructure isn't there like it is in the Halifax/Dartmouth area.
These two stations are economically questionable as-is, since coal is imported by barge. However, they have continued to endure since they are needed to supply power if the lines to other provinces are down for some reason. Keep in mind that the overland lines can and do experience failures during severe winter weather, and a large portion of the population relies on electricity to stay warm during the winter. Resistance heating is uncommon, but most heating systems rely on forced air or pumped hot water which requires electricity to operate. To fill the supply eliminated by taking Nova Scotia's coal plants offline, you would need either additional HV connections to other provinces, or you would need more natural gas power in the Halifax area. Either option would cost at least $1B. Add to that the economic issues of Sydney, and shutting down all the coal power in Nova Scotia becomes a much more difficult problem than most people realize.