Hope the devs will see this.
As the title suggest, it would be a good idea to give a clear post about the rules and NDA of the alpha testing phase, especially considering there's a flow of new players. The E-mail was rather short and gave almost no indications about it, aside from no permission to stream and post videos on the net.
An official sticky dev post on the forum would be way more visible in my opinion. Even if it's a summary and just a link to some rumes and agreements service.
And maybe even some of the Pre-Alpha testers might want to know if there's any change on this.