Similarly other biomass from agricultural waste is good.
Key word here is waste, because it'll naturally be cheaper and more efficient to use animal droppings or the inedible bits of food crops or post-consumer food waste or sawdust or offcut branches that are only going to be dumped in a way that releases methane. This can make them GHG negative, and so better than even renewables, though they can't scale as much so they're only part of the solution.
If that primary forest was sold and cleared to make planks, then that might be a problem for Canada to look into, but people using the waste from the process is not.
The article tries to imply that the whole forest was clear cut and burned for power but they don't actually state that, presumably because it's not true. It would be a much bigger scoop if it was.
Once we get rid of the need to burn stuff for power by rolling out more renewables, it'll probably still make sense to process waste biomass via pyrolysis to achieve carbon removal.