I have trouble with this. Even back in the 70s when I bought my first house, you only needed 20% down and you could then not pay mortgage insurance. If they do this, they will utterly destroy the housing market and the economy.
Also, even if this were the prudent thing to do, it would get all the politicians voted out. They are not going to allow this. You see how much screaming there is over the Obamacare website. You can imagine what would happen when the main source of most people's wealth disappears because of
illiquidity for the asset.
Also, this would destroy securitization, which is a huge source of revenue for crooked Wall Street manipulators.
The only way they go to this is create political cover for the shutdown of the GSEs so private capital can screw us on our mortgages. There may be some validity to that, but that sounds like a conspiracy theory, and.....naah, they're never true.