Then it wouldn't be possible to link to the page by copy-pasting the page title, which we've always been very careful to make sure it's been possible to do. I'm not saying this is prohibitive for wikis like Wikisource that rely so heavily on subpages, but it's something that needs to be kept in mind. What would be the best way to address that? Ignore it? Allow " ยป " as an alternate subpage separator?
Maybe have a little button in the right/opposite corner that you click and uses js magic to copy it to the clipboard maybe?