FWIW, I don't care for that one bit. Yeah, message IDs are pretty opaque in many cases, but at least they're not designed and built to be opaque. An example of what would be lost is the ability to find a message given one of these URLs in any other archive, such as one's personal mail archive. (Unless one sets up a mapping table to match this transform, which would be a big PITA.)
You mean going from an URL into actually finding the message, without looking at the actual archives site? Yeah, that wouldn't work. With access to the website, the message-id is right there of course.
But that's true, that's definitely a "lost feature" I didn't think of.
> Any access to the old message-id based URLs would automatically receive a > permanent redirect to the new ones.
If you remove the ability to find a message in the archive from its original message ID, I will be REALLY unhappy, because that will break lookups in the other direction (ie, given a message in my local files, go find it --- and its thread --- in the PG archives).
Oh, we will absolutely not do that. There's a reason we're still keeping redirects in place for the old style archives URL, which we stopped using in 2012...
On the whole I don't see any good reason to change this.
It is something that's fairly frequently requested, because they look bad. For one thing, it's regularly mentioned when discussion commit messages, because the "discussions:" links tend to wrap...