The liquidation preference is not the same as the value Treasury puts on their ownership stake in the GSE's, else the number would be 190B+ instead of 95B.
I'm not sure why there was such a decrease in valuation if they expect the g fee revenue to increase.
There are some details on how they calculate the worth based on a 2015 report (I couldn't find one for this year):
At any rate, the only news I see here in the budget is that they are expecting to increase the g fee to allow banks to compete with FnF. So open the market to competition and keep FnF profits for the next 10 years.