Yea, I read about this yesterday and it made me wonder if Mueller is coordinating his attacks on Trump with the DNC. What I mean is, it looks like the fund raising letter was written before the Ghestapo raid on Cohen's office. It is as if the DNC had the letter loaded before the raid because they fully expected Trump to fire Mueller after the blitz raid.
So Mueller, or someone on his Hillary's campaign staff team, contacts the DNC, lets them know about the upcoming raid, and tells them that Mueller is trying to get Trump to fire him. The DNC then writes and prepares the letter for release. When Trump didn't fall for the ruse and didn't take the bait, somehow the letter gets released anyway. The letter was probably put on some kind of release schedule and went out automatically.
The take away is, how did the DNC and Pelosi know that Mueller was going to try to get himself fired?