I think so because, in order to begin the assembly, you would need to invite Everett, and inviting him would require you 20+ likes from him, or so I think. Though I'm not certain if there's a chance to see them again at night in NC, I believe it would be better to load an old save from before sneaking up on Everett and Booner. This time, don't ignore it and talk to the commander. (keeping it secret will make him like you more, and blackmailing will make him dislike you). On the other hand, you mentioned that Feliar was killed, so yeah, inviting him to the official meeting will only be optional if you had saved him.