It can. Nationality is traced through the corporate layers to the individuals who ultimately own the shares, and treaty nationals must hold at least fifty per cent of the enterprise. A holding company incorporated in Quebec does not supply Canadian nationality of its own; its shareholders do.
Trace the shares to people and add up the percentages
Build the table from the bottom of the chain upward, naming each individual, their citizenship and their exact percentage. Hypothetical example: a Saint-Cyrille-de-Wendover distributor of powder-coating equipment plans to hold the American company through his Quebec holding corporation, of which he owns sixty per cent while a long-standing business partner, a citizen of a country with no qualifying treaty, owns forty; the effective treaty ownership of the enterprise falls to sixty per cent of one hundred, which clears the floor, but the same structure with the percentages reversed would not. Small changes matter here in a way they rarely do elsewhere, so run the arithmetic before signing anything.
Where the numbers do not work, the usual remedies are to restructure the holding, to have the treaty national hold the U.S. shares personally, or to accept that this particular partnership needs a different immigration plan. Note also that dual citizenship, shares held in a family trust and options that have not yet been exercised all need to be disclosed and explained rather than averaged away.