OP's solution is objectively worse, because it only reports access recency. Just because the table was or wasn't used recently, doesn't mean its safe to drop.
The code change may of landed the day before that disabled accessing that table, but the tool would warn that the table was still in use.
A quarterly cron job may access the table and go undetected if you look purely at the recency.
The rename strategy protects the data and offers easy rollback. This is a false heuristic.