Membership plugin - Regarding update-notifications.php - should it be uploaded if you have /plugins

Hello,
I have a general question about the update-notifications.php file. The documentation states to upload it to /mu-plugins. What if I don't have WP MU enabled. Do I upload it /plugins?
I did not do this for Buddypress because I didn't have MU enabled, but I'm starting to think I might need to.
Thanks.