Apple has released the eighth beta of watchOS 6

Networking

New Features
To enhance security, URLSession no longer sniffs the MIME type when the server sends Content-Type: application/octet-stream. (7820658)

NSURLRequest.CachePolicy.reloadRevalidatingCacheData and NSURLRequest.CachePolicy.reloadIgnoringLocalAndRemoteCacheData APIs are now available. (49660334)

URLSessionWebSocketTask and URLSessionStreamTask are now available for use in watchOS apps. (49779789)

Known Issues
The urlSession(_:taskIsWaitingForConnectivity:) delegate callback might not function as expected. (54309264)

  watchOS 6 Beta 8 released