Apple has released the third beta of macOS Catalina 10.15.2 to registered developers

Overview

The macOS 10.15.2 SDK provides support for developing apps for Macs running macOS Catalina 10.15.2. The SDK comes bundled with Xcode 11.2 available from the Mac App Store. For information on the compatibility requirements for Xcode 11.2, see Xcode 11.2 Release Notes.

Networking

New Features
Certain top-level domains (TLDs) such as .dev and .app are now in the Foundation URLSession and NSURLConnection HTTP Strict Transport Security (HSTS) preload list. An app which uses URLSession to visit a matching URL will always navigate to the URL as https://, and never as cleartext http://. See the HTTP Strict Transport Security (HSTS) Specification for more information about HSTS. (56247242)

Release notes