That is the I.G. report, the link to which was posted in a related thread a few days ago.
The I.G. states specifically that its review and this report were for the purpose of detailing the "what" of the certification process, in accordance with the Secretary's request as well as those from the Congress. And this report notes that any recommendations will be in later reports.
There are two reasons for this scope. First, the process is still underway. That is, until FAA completes the multi-step process it has outlined to return the derivative model to airworthiness status and to service - the test flights this week are just the opening step - it would be premature for the I.G. to issue internally-sourced recommendations. Plus, EASA, Canada and possibly other regulatory authorities also need to complete their work, prior to a full picture being in place.
Second, the I.G. isn't willingly going to extend outside its primary competencies. With the JATR, the Secretary's Special Committee, and if I'm recalling properly at least one or two other post-accident reviews of the process already done, the I.G. isn't going to masquerade as aeronautical engineering expertise internal to the bureaucracy. Even more so, when legislation already is percolating in both the House and Senate -- the I.G. most definitely will not want to issue recommendations until it has all, or very substantially all, of the dedicated (official) aeronautical expertise groups on record. A lot is riding on what emerges from the committees, both in the House and on the Senate side, and I.G.s at this level aren't politically tone deaf.