It's perfectly possible for immigration to be a net positive for the economy and for it to have negative affects on the availability of housing.
https://www12.statcan.gc.ca/census-recensement/2016/as-sa/98...
As the article states, 31,000 is 1.5 percent of rental accommodation. If we assume that half of the 300,000 immigrants rent, and that they tend to rent in couples, that's 75,000 rental properties consumed by immigration each year -- or about 3.5 percent. That's an additional 3.5 percent of rental housing stock each year, a much faster increase than the number of AirBNB rentals.
Regardless of whether you think immigration or AirBNB are major causes of a housing shortage, it's disingenuous to argue that immigration has less of an impact than AirBNB.
EDIT: It's also worth noting that construction is expected to slow over the next five years, whereas immigration is expected to grow.
https://www.cbc.ca/news/politics/immigration-canada-2018-1.4...
https://www.on-sitemag.com/construction/end-of-an-era-20-yea...
Rallying against AirBnB is so silly -- no matter how you slice it it's always a minor factor in self-inflicted "housing crisis" scenarios.
https://www.statista.com/statistics/443063/number-of-immigra...