According to HERA, if FnF were released from conservatorship right now they would be instantly classified as "critically undercapitalized" and would be put right back into conservatorship, if not receivership.
Your story stopped working once they both surpassed a combined capital of 50-60 billion.
Again, you're wrong about FnF's capital levels. Learn the difference between net worth and regulatory capital (both minimum/leverage and risk-based).
But I bet you keep repeating it even if the seniors get forgiven and warrants sold back.
The seniors getting written down or converted to common would add $121B to Fannie's core capital and $72B to Freddie's, so my story certainly would change if that were to happen.
The warrants have nothing to do with FnF's capital levels, though.