grep -rl '# Copyright © .* Pleroma' * | xargs sed -i 's;Copyright © .* Pleroma .*;Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>;'
This will 'time travel', i.e. change the inserted_at and update_at fields of the object in question. This is used to backdate things were we used sleeping before to ensure time differences.