This guy gets it.

Costs trickle-down... Profits don't.

No. Landlords do not "produce" rooms by taking raw materials and transforming them into goods. In the current market, the rent is determined by how much the marginal renter is able to pay. Increasing the cost to the landlord doesn't magically increase the renter's ability to pay

"A" government[1] could telegraph that major (as major as is necessary) policy changes are coming that will affect SFH investors in a detrimental way, and that it would be in their best interests to prepare accordingly.

If this does not happen, I suspect Mother Nature will eventually intervene, and that usually doesn't go well for anyone.

[1] I do not presume that any arbitrary Western government is actually capable of this in the real world as it relies on many prerequisites, some of them policy, some of them psychological/ethical.

Where would these two landlords be living? Both would be exactly the same if the landlord doesn't rent.