The journal restart can be observed on zesty as well.
However, the journal is not corrupted, the renaming and replacing took place as a safety measure due to unclean shutdown.
$ sudo journalctl --verify --file=/run/log/journal/*/*
PASS: /run/log/journal//6ff4e09ca827435bbe1b6efc2236a105/system.journal
PASS: /run/log/journal//6ff4e09ca827435bbe1b6efc2236a105/system@00055289b166aebb-17bfde05076f84d2.journal~
PASS: /run/log/journal//6ff4e09ca827435bbe1b6efc2236a105/system@b7f19f66c640442d854033592fdedbb6-0000000000013de4-0005528690181932.journal
PASS: /run/log/journal//6ff4e09ca827435bbe1b6efc2236a105/system@b7f19f66c640442d854033592fdedbb6-0000000000013569-000552843559e7e6.journal
PASS: /run/log/journal//6ff4e09ca827435bbe1b6efc2236a105/system@b7f19f66c640442d854033592fdedbb6-0000000000012d03-00055282a0e0b31b.journal
PASS: /run/log/journal//6ff4e09ca827435bbe1b6efc2236a105/system@b7f19f66c640442d854033592fdedbb6-00000000000124a8-000552806e21938c.journal
PASS: /run/log/journal//6ff4e09ca827435bbe1b6efc2236a105/system@b7f19f66c640442d854033592fdedbb6-0000000000011ca8-0005527efc9ec6de.journal
PASS: /run/log/journal//6ff4e09ca827435bbe1b6efc2236a105/system@b7f19f66c640442d854033592fdedbb6-00000000000114a4-0005527d2438261c.journal
The journal restart can be observed on zesty as well.
However, the journal is not corrupted, the renaming and replacing took place as a safety measure due to unclean shutdown. /run/log/ journal/ */* journal/ /6ff4e09ca82743 5bbe1b6efc2236a 105/system. journal journal/ /6ff4e09ca82743 5bbe1b6efc2236a 105/system@ 00055289b166aeb b-17bfde05076f8 4d2.journal~ journal/ /6ff4e09ca82743 5bbe1b6efc2236a 105/system@ b7f19f66c640442 d854033592fdedb b6-000000000001 3de4-0005528690 181932. journal journal/ /6ff4e09ca82743 5bbe1b6efc2236a 105/system@ b7f19f66c640442 d854033592fdedb b6-000000000001 3569-0005528435 59e7e6. journal journal/ /6ff4e09ca82743 5bbe1b6efc2236a 105/system@ b7f19f66c640442 d854033592fdedb b6-000000000001 2d03-00055282a0 e0b31b. journal journal/ /6ff4e09ca82743 5bbe1b6efc2236a 105/system@ b7f19f66c640442 d854033592fdedb b6-000000000001 24a8-000552806e 21938c. journal journal/ /6ff4e09ca82743 5bbe1b6efc2236a 105/system@ b7f19f66c640442 d854033592fdedb b6-000000000001 1ca8-0005527efc 9ec6de. journal journal/ /6ff4e09ca82743 5bbe1b6efc2236a 105/system@ b7f19f66c640442 d854033592fdedb b6-000000000001 14a4-0005527d24 38261c. journal
$ sudo journalctl --verify --file=
PASS: /run/log/
PASS: /run/log/
PASS: /run/log/
PASS: /run/log/
PASS: /run/log/
PASS: /run/log/
PASS: /run/log/
PASS: /run/log/
Was the journal corrupted in your case?