The HML snippet created leaves off HTTP/HTTPS from the link to the map, and lets the webserver resolve that, so as to avoid mixed content issues. This also means though that the map won't render for those using desktop products like Dreamweaver on a local machine to design their page. This has created confusion for our web publishers, thinking there's a problem with the map they're trying to reference.
A warning regarding this on the dialog box would help. Perhaps after the Copy and paste HTML to embed in website text, add something like (URL will not resolve on local machine) or (webserver will insert http or https).