I wish I knew more specifics, but I did take a look back at the negotiations updates. The negotiations over Scope appear to have ended before filing for mediation. That could mean it's mostly complete, but it may not. Since the latest updates have all referenced negotiating issues like compensation and benefits, I think it's reasonable to conclude that most of the scope section is completed. Perhaps it's one of those sections the NC and company are meeting outside of mediation to finalize the TA language.

It's pretty typical to have many sections remain open until the whole thing is TA'd. I feel like a kid waiting for Christmas, except there's no set date to open up the presents. It's a frustratingly long process, with little information to allow us to quantify progress. At least in this case we can do more than just send a wishlist to the North Pole and actually get "Santa" to meet our proposals.