Will I have to reschedule the update?

There is no set schedule for when updates are released. The current version is iOS 15.5.

The following has information about how to schedule automatic updates and how to manually update. Update your iPhone, iPad, or iPod touch - Apple Support

Everytime Apple decides to offer you a new release, containing bug corrections, new features and (most of all) security patches.

But nobody here has a "calendar/plan" to tell you when it happens.

Regards

Giulio

Apple never forces you to update but new updates usually have new features and important security updates that are usually recommended for all users. You can always check the description of the update for more information.

Update your iPhone, iPad, or iPod touch - Apple Support