I've always noticed the tone of the IBT emails and meetups to be pretty negative. This is likely some combination of the people involved and negotiation tactics and I wouldn't worry about it.

The company emails have changed drastically since the law firm stopped writing them, but they tend to be parabolic - sometimes overly optimistic, and other times completely negative. It is good to see progress being made in the scheduling section, which is currently sub-standard even by low end regional standards. At the end of the day I think the company is being forced to finish this thing up by market forces... They could probably string things along for another two years without getting called out by the NMB, but it would fatally harm the company in the long run with attrition and hiring.