Earlier quoted context omitted.
The value of housing comes from how much you can charge people who want to live in them. That number doesn't change because foreigners can't buy.
By definition it will. Fewer potential buyers always means lower top prices. Especially in this case, where the whole point is to prevent rich foreigners from outbidding poor locals.
A: People who want to live in a city need housing and are ready to either 1: pay X/month (rent) or 2: buy the house.
B: This law do not create new unit to be rented or bought, and do not do anything for the cities attractiveness, IE the migratory trend will stay the same
C: The renting price is complex and while location and regulation do have an effect, the price is based on supply and demand, not on "how much did you pay for this house" (unless you have rent limits in canada).
D: The buying price is complex but also half based on the renting price. I think AirBNB jacked things up, and we now see housing as a commodity so the number could be higher, but when i was a kid the common sense was: monthly rent * 12 * 20 > house price: buy, else don't.
If A,B, C and D are all true, then i don't see how this law can change prices. If i'm wrong on any point, it might.