Which proposal? There's one proposal for Python interop that's already accepted (Proposal: Introduce User-defined "Dynamic Member Lookup" Types), and I don't know the status of [Pitch] Introduce user-defined dynamically "callable" types
The Tensorflow-thingy is a different beast, though.
There's not much information available now, but my impression is that this could question the whole concept of Swift Evolution in it's current form...