Most posts on meta seem to invite answers, which is what the SE engine seems to be good at. But there are some posts that seem more like announcements and less like anything that can be answered. On the other hand, they are useful announcements. Is meta the right place for non-questions to be posted (as opposed to, say, the blog, or some other announcement forum)? Note that these sorts of posts are neither a bug report, feature request, call for discussion, nor request for support.
Yes, meta is the right place for these types of questions, even if they aren't really "questions" per se.
Actually, you're asking in the right place about these things. When Meta was first introduced it was meant to serve as a space for people to discuss the site without discussing the site on the site. (Still with me? Okay!) It was actually one of your mods, Kyle Cronin, who helped fight for and organize a MSO community before MSO was a thing.
Now, as we've grown and our network diversified, meta has become more than discussion-worthy queries -- it's also become a way to rally the community around events, cleanups, and contests. Meta has evolved just as our sites have evolved.
Think of it like this: not all discussions yield answers, and not all answers are responding to questions. Meta is a good place for those questions and answers. :D