So 14.3 public release today and Fitness+ gets enabled OTA on Monday? Otherwise, 14.3 RC(GM) today and public on Monday.
Interesting tidbit from Apple release:
Apple Fitness+ will be available Monday, December 14, and requires iOS 14.3, watchOS 7.2, iPadOS 14.3, and tvOS 14.3. For Apple Watch users, Apple Fitness+ will automatically appear as a new tab in the Fitness app on iPhone; the Fitness app for iPad will be available to download from the App Store; and on Apple TV, the Fitness app will automatically appear once users upgrade to tvOS 14.3.