I wondered if Kelly is there to ensure POTUS request to share documents is followed?
Good speculation. I don;t know. If WH is not there, and DOJ persists in unreasonable stonewall, the only thing that happens is escalation by Congress to contempt vs. Rosenstein, and maybe additional delay in getting this information to the public, where it belongs.
At this point, Congress can't be trusted any more then DOJ/FBI. Both institutions will hide their actions aimed at derailing the Trump agendas.