As part of password expiry, global_priv now has a password_last_updated field.

This isn't exposed in any native SQL like 'SHOW CREATE USER', nor is it set-able except by modifying system tables directly.

Without this feature, a restore of native SQL tables with have the password_last_updated containing the current date of restore.

MySQL-5.7/8.0 has this value in the mysql.user table as password_last_changed column.
MySQL doesn't expose a native SQL mechanism for setting this either.

Postgres has a "VALID UNTIL timestamp" in their CREATE USER/CREATE ROLE