OAbot is a tool to easily edit articles to make academic citations link open access publications (see list of edits made).
Wikipedia links to hundreds of thousands of paywalled sources. Our community does not prohibit or even discourage citing paywalled sources, but at the same time there is absolutely no prohibition on surfacing open access (OA) versions right alongside those citations, as long as the link does not violate any copyrights. Indeed, a good citation will have as much information as possible to let the reader find (and use) it in the way that is easiest for them.