It was the prosecutors that abruptly dropped
all charges, so unless the FBI is somehow trying to take over and make the fake anthrax letter the priority prosecution, there evidently was something new that came to light, since the only reason they would do that is if Smollett took a plea deal or otherwise plead guilty (which, so far at least, has not been revealed).
The idea that prosecutors just suddenly decided that he'd been punished enough--as is implied in the
following statement--is just ridiculous, so clearly something else has happened we don't know about:
“After reviewing all of the facts and circumstances of the case, including Mr. Smollett’s volunteer service in the community and agreement to forfeit his bond to the City of Chicago, we believe this outcome is a just disposition and appropriate resolution to this case,” the statement from spokeswoman Tandra Simonton said.
Smollett paid $10,000 in bail to get out of jail after his arrest.
So, for committing 16 felonies, the prosecution is basically saying, "Eh, we'll take $10K and a few hours of community service out of the goodness of our hearts," but only after alluding to something discovered as a result of a "review" of the facts and circumstances. Seems unlikely.
Unless there was some other pressure being put on the DA's office, but that would be an awfully risky political move either for a Dem or Repug.
ETA: Here's something from
CNN:
Parts of the case will be sealed, one of Smollett's attorneys said.