Hi there. Had a lengthy back-and-forth with Apples review team and they insist that the PIN flow is violating section 11.1 “Apps that unlock or enable additional features or functionality with mechanisms other than the App Store will be rejected”. Entering a PIN on an external device is fine, but entring a PIN on the AppleTV is a no-go.
I can’t use any of the other Authentication flows for a lack of a Webview or any universal way to transfer an URL to the device. And I have no Access to XAuth (and it seems to be abandoned anyhow?)
Apple suggests to discuss this with Twitter, so I’m posting here. I’m also happy to provide more details if contacted directly. I can help working on a solution, as I have a finished App waiting to ship. But as it seems, currently there is no valid way of signing in with Twitter on tvOS.