You should know, I stopped clicking on your links a long time ago when I realized you didn't know a thing about the real estate market or basic economics, so you can stop posting them if you like.
And...to answer your question..."What makes you think there will be less availability for first time home buyers?"
The answer is "History." All you have to do is look back at how loans were distributed BEFORE FNM/FRE and you can see how they'd be distributed AFTER FNM/FRE.