Thank you for your question!
Typically, I am not interested in other things but knowledge. This blog is not meant to be a justification nor clarification on how other BKs wish to behave. Please bear that in mind.
Your question is not complete. Let me complete it:” Is it true that if you are a BRAHMIN soul and you are not maintaining purity you are not allowed to meet Baba in Madhuban?
That is true. Thee are many who may call themselves Brahmins but if they do not practice that particular maryada; to my knowledge; they are not allowed to meet Baba “physically” in Madhuban.
HOWEVER, as you mentioned there are many VIPs who are allowed to meet Baba; that is because BapDada has given the instructions to do so. Want proof? 🙂
You can read this recent avyakt Murli https://explore7.files.wordpress.com/2012/10/avyakt101412-3of3.png which is actually from 1975.
Here clearly BapDada mentions the reason why as well as the disclosure that “it will require an unlimited intellect” in our part to understand that these souls will not be “regular Godly students” but still they can be instruments for service through their own experience while still obtaining what they wish to attain. Through them is how regular “followers” will understand about God and this knowledge… without understanding.. 🙂