“We will never know” is such a contradictory statement. On the surface, it implies the limits of our knowledge while simultaneously indicating that the author possesses the omnipotence required to know what humans will learn throughout the entirety of our future. Add it to your list of things to never write.
That's a very narrow reading of it. There's always an implicit "to the best of our current knowledge" caveat with every sound scientific statement. And it's true, to the best of our current knowledge, we can never know what it's like inside a black hole or very close to the time our universe began because the physics that we know tells us no person or probe can ever go there and come back to tell. If you're no so generous as to accept the implicit caveat you just end up being fun at parties because you go around and tell people to "never say never and always avoid always".