You do realize that's all complete bull shit, right?
It's faker than NASA's ISS videos. If there was a large object already moving through our solar system, we'd fucking know about it. Perhaps they'd try to hide it from the general public, but considering these "hypotheses" have been around for my entire life, I'd guess they continue to be pure speculation. Especially, since they never seem to come with visual confirmation, despite being well within range of observation capabilities.