It is possible, but depends on what software is creating the RSS feed file. I think the “guid” element is the main part of an RSS entry that readers check to determine “is this a new post?” So, theoretically, if the software creating the RSS feed updated the guid and the published date, the content of that entry would show up again in a reader as if it were a new post. Depending on the software, it might be easier to keep a separate RSS feed where each entry is a short text and link to the resources page: “Resources page updated: [link]”