I agree that many current owners and developers won’t have the option of keeping their excess (non-owner-occupied) real estate as rentals.
That’s what short sales and foreclosures are all about.
Some units may have to be purchased and foreclosed more than once before reaching a price where an investor is willing to hold long-term as a rental.
Personally, I won’t be buying any rental units until gross-rent-multipliers are back in the 8-10 range. That means the $2500/month rental is worth $240-300K to me today.
How does a $700K 2 bedroom condo downtown become a $300K condo? I don’t know but that’s what I’m expecting. There will probably be many foreclosed “homeowners” and bankrupt builder/developers along the path.