Rejecting a Qur’anic claim established decisively and not accepting a particular nondefinitive narrated detail are not identical questions. The underlying Night Journey is stated in the Qur’an, while grades of transmission differ for the heavenly ascent and individual further stations.
The classical discussion describes rejection of the widely reported Ascension as an innovation. That technical classification must not be treated as an unrestricted licence to pronounce individual people unbelievers; the exact proposition, level of proof, and intended meaning matter.
Keeping these distinctions clear allows doctrinal evaluation without indiscriminate judgments.