LinkTwo things this could mean:
1) the autopsy is substantive and very critical, and hopefully will lead to real and permanent change within the institution (which I think everyone, irrespective of ideology and attitude towards the Democratic Establishment agrees needs to happen).
2) the autopsy is a giant pat on the back and Congressional Democrats want to avoid grassroots anger.
Either way, I'm fairly ambivalent about publicizing these reports to begin with. Transparency is all to the good, but if you can avoid the narrative that surrounded, for example, the RNC 2012 autopsy it's probably worth keeping your plans on the DL.