Sounds like another effect of the way-too-low interest rates, and an interesting crisis to come.
It's an interesting securitization to be sure, but I don't know about this doom and gloom crisis scenario you are speaking about.
Long term buy and hold type loans meant for investors are typically based the on debt service coverage ratio meaning the tenant's rents need to cover the mortgage payment by a certain %. These are hovering around ~%8 which usually makes for a pretty thin margin on a cash flow basis. As with any investment, if you are banking on appreciation and that is all you've got, I'd worry. Perhaps not so much so in the booming area this article references - UNLESS funding dries up for all the hot commodities coming in.
This is all due to money chasing returns it can't get due to low interest rates.