If the talks were to fail it would be a simple thing for them to say - looks like our only hopes are now CoT.
No violation of NDA and we would know.
However Downix and Irish Girl both have been here in the last month saying - work still ongoing slow but sure.
There are always two issues to consider when being a party to an NDA. The first one is the obvious one: recognizing there are legal ramifications for violating the agreement. But there's a second one that's usually more important: deals require trust, and someone attempting to game the NDA is instrinsicly untrustworthy: if that's how they are going to treat the NDA, how will they treat any other contract we try to have with them. So its not just about the letter of the law, its also a form of test to see if you are worth dealing with. People who push the envelope on the NDA may or may not face legal repercussions, but will almost certainly find themselves in a bad place when it comes to any future negotiations, assuming people don't just plain walk away from them.
This is important because its rare to find a genuinely air-tight contract; even NDAs have all sorts of loopholes. But you attempt to exploit them at your own risk. Knowing this, people tend to be extra careful when dealing with NDAs when a deal is still in the works. But when it all falls apart, leaks tend to happen much more frequently because the need to preserve the trust of the situation is lower. More people are more likely to talk about more things. If the deal has completely collapsed with no hope of restarting or salvaging, we'd hear about it. No matter what the NDA says, even if it says they can't talk about the negotiations even if they fail, there's always a loop hole that allows you to say at least something. The fact that people aren't saying anything suggests that a deal is still possible. If it were not, we'd hear something, NDA or not. No NDA can prevent you from saying "I've decided to no longer spend any time on any project which has the goal of negotiating the rights to any part of City of Heroes with any party." If everyone involved stated that, we'd know it was dead, even though it says nothing about any negotiations that might be happening now.