Don't stress, LKML is mirrored in many places
Like any well-known mail list, LKML is mirrored in other places, e.g.
http://linux-kernel.2935.n7.nabble.com/
and anyone who cares can use tools like PonyMail (https://ponymail.incubator.apache.org) to create their own archive.
So while the home location might be fragile, it can be re-established in days or weeks, and the history won't be lost.