TVTopShelfContentProvider and Swift 6 Concurrency

I have a TVTopShelfContentProvider that implements

func loadTopShelfContent() async -> (any TVTopShelfContent)?

When running on Xcode 26 b5 I am seeing the following error in swift 6 mode.

Non-Sendable type '(any TVTopShelfContent)?' cannot be returned from nonisolated override to caller of superclass instance method 'loadTopShelfContent()'

I'm not sure exactly what's changed here as it used to compile just fine but it's unclear now how I can work-around this error or how the API is supposed to be used.

The following definition is enough to trigger the error in Swift 6 language mode.

import TVServices

class ContentProvider: TVTopShelfContentProvider {
  override func loadTopShelfContent() async -> (any TVTopShelfContent)? {
    return nil
  }
}

I can "fix" it by adding @preconcurrency to the TVServices import but it seems like this API is unusable currently? Or maybe it's user error on my part?