For example, these pgp signed emails are signed with the key with short ID 5EB7CB21 which is not the well known key, does not exist in old keyserver dumps, and has a pref-hash-algos list of "8 2 9 10 11", which is the list that GNUPG started generating a year (commit e50cac1d848d332c4dbf49d5f705d3cbbf074ba1) after the date on the key. The well known key, which the new key claims to be generated within 24 hours of, has "2 8 3" which was an the prior list of hashes.