It remains a hypotheses - in that a majority, when they look back, can recall such things, but a few have flatly denied such experiences. So it remains an open question.
Those who strongly believe the world is just the sum of the senses (then bizarrely also believe in fantasy divinities!) will tend towards materialistic doctrines, utilitarianism, relativism, behaviourism. Those who use such constructs to control others do not necessarily have to believe in them, but those who go against any oppressive measures must surely have some different experiences to support their position. Not sure.
The oppressors - the oppressed - the dissidents.
rather uneven fight!
Neo was not there to save Zion; he was there to save the Matrix.
Indeed, the algorithmic matrix throws up two anomalies - the virus (Smith) and the antivirus (Neo) - and if unresolved will destroy the matrix. Their resolution creates a slightly different matrix that in the future will throw up another anomaly-pair ;-)