There’s a pretty good video on FR someplace, of Chavetz ranking down the FBI spokesmouth after he disclosed they had decided which emails to release and what would be redacted.
Chavetz asked him where in the Constitution does it give that authority, and how his constituents had elected him to see the files, and how his committee members elected him to chair the committee and view the information.
He then asked a couple more questions which the FBI hack declined, or answered no.
He then produced a packet of paperwork, subpoenaing the FBI to produce all the un-redacted e-mails...the complete file.
He said: “Consider yourself served”.
These extra emails were released by the FBI on purpose. Why? So they could use it as an excuse to resist releasing any more (the really damaging ones). In retail it’s called a loss leader.