Plan expiration notifications are now available! Your members will now get a "Plan Expired" email when their plan expires.
You can also turn on the "Plan Expiring Soon" email so members will be notified X days/hours before their plan expires. You can edit the wording and/or disable these emails in Customize > Member Emails.
You as the admin can also receive emails when a member's plan expires. Turn this on by going to Customize > Sign Up Experience > "Email me when a member's plan expires".