I guess Sega probably owns the NDA now, so please respect it still.
I'm replying to this as someone that has studied business law, among other things, as part of my degree in business administration. I feel it's a good time to chime in, as I keep seeing this "Sega owns the NDA" stuff pop up. Right now former testers, and community sites such as CoH2.org, are respecting the NDA as part of an honor system more than anything else. That, or they're simply not familiar with contract law, and don't realize that the NDA no longer carries weight.
The reality is that THQ is bankrupt, with just a skeleton crew on board to manage the split of assets. THQ lost the rights to Company of Heroes, THQ no longer owns Relic, and there's absolutely no way that the THQ legal team would pursue anything related to CoH at this point. Additionally, a third party (i.e. Sega) cannot simply acquire an existing contract as is just by purchasing a subsidiary of a company in which a contract existed. The NDA was with THQ, not Relic. Sega purchased Relic, not THQ.
Essentially Sega would have to get every alpha tester to accept a brand new NDA in order to retain the terms of the agreement. That's not realistic, and it'd be a waste of time. The only thing Sega could react to anything related to the alpha at this point would be copyright claims against the distribution of multimedia (i.e. screenshots, and video), under copyright law, since they now own the rights to the IP.
With that said, I'm among those willing to honor the agreement, despite the situation with THQ. I would like to see CoH 2 succeed, so if the people behind it feel it's not the right time to discuss the game yet then I'm willing to wait.
Edit: I just noticed something quite amusing while evaluating the agreement again. There are a number of flaws that I've found in the agreement, but the biggest by far is the failure to link the agreement to the actual alpha test. The entire agreement is based around the "Beta Test", which hasn't even begun yet. Essentially that one mistake pretty much invalidated the agreement in relation to the alpha test, and this is why it's so important to pay attention to wording when drafting legal agreements.