If they received the right Jesus they would of never been a part of Mormons and JW's to be in that cult.
It would be unless they received the right Jesus and got out of that cult.
Yes; if they received the right Jesus they would very likely have discernment about the teaching of those cults.
However, I consider that there may be some who are not very intelligent who received the right Spirit but for whatever reason attend congregations that are of the cults in question.
In their hearts they would know the truth and would be grieved every time the teaching is presented of Jesus not being God (as with the JW's) or of being a separate Person from God the Father (as with the mormons).
In their personal Bible reading, they would struggle to hold onto the truth that is contradicted by their teachers; because in their hearts they would know the truth and there would be suffering in them because their mind does not align with what is in their heart as their teachers contradict the truth that is in their hearts.
Their heart would only be satisfied in their minds knowing the truth; so they would continue to be Bereans (Acts 17:10-11) concerning what they are taught and would eventually have the courage to leave the cult that they are in; if not physically, then at the very least mentally and emotionally.