> Now while the total supply of housing hasn't changed (and might even have increased on the margin), there will be less supply of rental units on the market.

> Now while the total supply of housing hasn't changed (and might even have increased on the margin), there will be less supply of rental units on the market. But then you’d also have less renters in your scenario because a renter became an owner. Less renters would mean a decrease in demand for rentals. The only situation which hurts buyers and renters is when the unit is left empty to artificially decrease supply.