Be aware that there are normally two different taxes applied to vehicles sold in Canada: one is a federal government tax, called the GST (Goods and Services Tax), the other is a provincial government tax, generically referred to as PST (provincial sales tax).
My own guess, based on having lived in Canada most of my life, is that you will not be able to get a refund of either tax if you plate the vehicle in Canada after you buy it (the only exception being if you get a 10 day 'temporary vehicle permit' that is generally used only for driving/riding from the place of purchase to the border with the USA).
All of the various provinces (which administer the licence plate schemes) want to see proof of tax paid before they will give you a licence plate. The motor vehicle licence offices have a very keen interest in this subject because private sales of used vehicles between individuals also attracts tax. If you can't prove that you paid the tax at the time of purchase (i.e. present an official receipt from a motor vehicle retailer), then you will get assessed tax at the licence plate office before you can buy a plate. The tax assessment will be based either on the price you paid or on the fair market value of the vehicle/motorcycle, whichever of the two is higher.
Unlike Europe, we don't get very many people buying vehicles in Canada for export to anywhere except the USA. Hence, I don't think there are any programs existing to support operation of a vehicle on 'export' plates, as there are in Europe.
I could be wrong, and there might be some program I am unaware of, but I kind of doubt it.