Welcome back!
Basically this argument includes various fallacies and factual errors, but on its face, it ignores the overall point. The argument has never been that private banks had absolutely no role in any of the crisis. This is basically an implied strawman. The main point about Fannie and Freddie is that they were basically government corporations (and now they are undeniably that), and they had an implied government backing…and they were there to purchase the notes originated by lenders. If that secondary market dominated by the GSEs did not exist, the lenders would not have had the incentive to make such risky (i.e. bad) loans.
I outlined what went on in a bullet point format here. Also, as brought up here in that same thread and in the Inside Job discussion, the only “deregulation” anyone can ever seem to mention is “Glass-Steagall”, and even then they don’t even know what it is.