Apple will allow users to forgo the upgrade to iOS 15 and will continue to provide security updates for iOS 14.
The company says…
iOS now offers a choice between two software update versions in the Settings app. You can update to the latest version of iOS 15 as soon as it’s released for the latest features and most complete set of security updates. Or continue on iOS 14 and still get important security updates until you’re ready to upgrade to the next major version.
Previously, Apple would prompt users to update to its new software for the latest security updates and features.
You can learn more about the upcoming features in iOS 15 here.