It is a fact that Rav Moshe Sternbuch has said it is too early to speak about Nibiru [see video here by Rabbi Daniel Travis] and also Nir ben Artzi, when asked about Nibiru, replied that he is aware of it, but did not have any information to add, therefore he does not discuss it yet [see comments here]. I find it quite strange that if Nibiru is indeed going to show itself on or around Purim,