I would say that the,'the end never justify the means.'It is all about the process.
A white lie in order to spare suffering is still a lie(controlling)even when it is wrapped in a golden bow(A higher rational).As I wrote before,one can rationalize anything.Maybe a persons kharma is to know this cruelty?
It sounds like withholding the truth is a product of ego also.Besides it's not the truth we react to; it is what we individually attach to this truth that we react to.How do you already know how or what someone else will attach?As such how they will react?
Need to know is a form of controlling.It controls the information,data,knowledge,truth by only being offered to those selected to recieve it.Who makes this selection?Who decides?
Your last sentence,"An ego that is doomed to nonexistance when the spiritual path is followed to its ultimate end--merging with God,"is evidently something that you believe or have been taught is true.Evidently you use this as a truth.What do you base this truth on?