Legally, the situation has not really changed. She's never going to prison. Ever. But it's the political situation that's changed.
If Comey played it by the book, he would have handed over the results of his investigation and walked away, leaving it with Lynch, Obama, the Clintons and the media to spin it.
Lynch has changed everything with this statement, again politically not legally.
Not bound by professionalism any longer, Comey is obligated now to say "indict" or "she didn't break any laws", and she absolutely undeniably broke laws regarding her handling of classified data.
Comey cannot maintain his professional reputation and respect in the intelligence community without publicly listing her crimes and recommending she be prosecuted for them. Politically that's a stake in the heart, regardless of the legal machinations down the road that keep her out of jail.
There are many instances of situations that may appear under nominal control, yet flip to chaos in a wink. 6/28/1914 is a famous case, yet there are countless others, hence "Cry 'Havoc!', and let slip the dogs of war".
The point being, BHO and the entire DC mandarin class has been desperately trying to maintain the status quo. Trump as we know has upset that equation. Now, there is a real & present danger that BHO's post-presidential career could be impacted by the Hillary capers.
It's clear - at least to me - that BHO, Jarret, Lynch, et al planned on having LL meet with Bill in order for Lynch to be able to recuse herself. This is nothing more than a firewall to begin protecting themselves from the fall out of Hillary going down. In other words, the CIA/NSA intelligence community has won.
Once a break occurs in the battle lines, that's when the route/massacres begin. (It's why it's important to try & have an orderly retreat.) It may seem unlikely, impossible even, at this point that justice may win out (ie Hillary convicted), but history has shown that events can turn on a dime.
BHO needs/wants to have a respectable career when Trump is president. This is his team's way of preparing for a smooth exit.