Not necessarily. The ruling merely said it was unconstutional. It did not say that the Queen was misled or that it was intended to thwart opposition.
Parliament could just resume as if nothing has happened and BJ will remain PM. It has been suggested that he could prorogue again, but the ruling states that 4 6 days is the conventional period of prorogation to prepare for the Queens speech, so I think if BJ did choose to prorogue again, he would face another challenge in the courts if it exceeded that period and, although I am not a lawyer, I would hazard a guess that it would be possible to get a court injunction so that the proroguation could be instantly suspended, pending a full argued appeal before the Supreme Court (again)