Enabling this is trivial, the question is: is there any reason we *can't* enable this? Who's responsible for this service and might know of exceptions like mixed-content, or HTTPS-incapable tools which rely on it, etc? [note this a generic message being tacked into the description of several similar tickets]
I don't see any mixed content in simple checks, and it seems to not use proto-absolute URLs in general. Since this site is clearly for human consumption, I'll probably enable the HTTPS redirect shortly if no objections come up.
@Chmarkine: not sure - those changes are still in puppet, and I've confirmed the backend server for it today (bromine) still has that config deployed as well. But in practice, http://transparency.wikimedia.org/ does not return a redirect... in any case, when we fix it at the cache_misc level it'll be fixed for sure.