There is no harm in believing what your guru told you (snake is a rope). But you should not concoct new theories and fantasies about being asleep in Vaikuntha or claim that other acharyas support such concoctions.

Worse yet is calling people who believe in the shastric (Upanishadic) definition of tatastha sakti 'impersonalists' and other silly names. The idea that parishads of Lord Krsna fall from Goloka Vrindavan to engage in this material world has no basis in shastra. Neither does it ever appear in the writings of the six Goswamis or subsequent acharyas. That is why it is safe to conclude that Prabhupada preached like that to his Christian and Jewish disciples because they were familiar with the 'fall from Eden' concept.