The episode.rss.xml should generate the feed for posts in the episode directory, the blog.rss.xml does the same for the blog section.
Since 0.146, it’s no longer using these templates to create the feeds; they seem to be the default feeds? Is this a function of the new template lookup perhaps?
We (I) should have done a better job handling the backward compability of the /layouts/section case, but I do believe that breaking some eggs to get to a better place was needed.