Apple released Xcode 12.2 RC yesterday, 5 Nov 2020 (same day they released iOS 14.2). I just downloaded the RC here (under the Applications section): https://developer.apple.com/download/
Per the release notes:
Xcode 12.2 RC includes SDKs for iOS 14.2, iPadOS 14.2, tvOS 14.2, watchOS 7.1, and macOS Big Sur 11. The Xcode 12.2 release candidate supports on-device debugging for iOS 9 and later, tvOS 9 and later, and watchOS 2 and later. Xcode 12.2 RC requires a Mac with Apple silicon running macOS Big Sur 11 or later, or an Intel-based Mac running macOS Catalina 10.15.4 or later.
From Xcode 12.2 RC, I am now able to run and debug iOS apps on my iPhone XS (which is running iOS 14.2).
It's maddening how Apple will release iOS updates without releasing the corresponding Xcode updates. This is not the first time. The least they could do is prominently warn us so we don't accidentally update iOS to a version that isn't supported by the released Xcode version.