Does buying a business through a Canadian holding company change my tax exposure as a non-resident?

Yes, meaningfully, though it changes the mechanics of your exposure rather than eliminating Canadian tax altogether. Using a Canadian holding company to acquire a Canadian target is a common structure for non-resident buyers, and it affects things like how profits are eventually repatriated to you outside Canada — dividends paid up from a Canadian corporation to a non-resident parent are generally subject to Canadian withholding tax, though this can sometimes be reduced under an applicable tax treaty depending on where you're resident.

The structure also affects how acquisition financing is treated: rules limiting the deductibility of interest on debt owed to related non-residents can come into play depending on how the purchase is financed, and how the Canadian holdco is capitalized can meaningfully change the after-tax return on the investment. It can also affect Canadian tax on a future sale or wind-up of the business, since a Canadian holding structure changes who is disposing of what, and when.

Because these rules interact heavily with tax treaties and the specific way a deal is financed, non-resident buyers should have Canadian and home-country tax advisors review the proposed holding structure before committing to it, not after the acquisition is already funded.