Currently, the NR team do not have a reliable way to guarantee that the provided link is the link to a valid Changelog. Unless someone finds a solution, this feature will remain on the backlog
Explanation: the catalog contains modules coming from NPM. What links GitHub (or other) to NPM is the repo link defined in the package.json. This link being provided by the author of the module, it's subject to errors (bad url, private repo, origin url for fork...)