I created a topic in the private Staff category for preview, and next day moved it to a public category. At that time it showed up in the forum’s RSS feeds, as expected. But the RSS item’s pubDate is the original (private) creation time. Because this is quite a bit older than when the item appeared in the feed, it causes the item to be ignored by some feed readers (Bazqux, at least). Also, the discourse matrix plugin which normally announces all new topics did not announce this one. I think this would be more robust if RSS feed items’ pubDates could be the date when the topic or post was made public-accessible. (I’m not sure which version of RSS or Atom discourse is using, but Atom 1.0 feeds can include both a published and an updated time, if it helps.)