This claim is shared by some teachers, professors etc.
Sharing one's most valuable insights and accept the prospects of his students be coming part of a "knowable state of an advanved mind", is not something every teacher is consciously willing to do.
This thesis is in some aspects compatible with the political philosophy associated with the right, that admits Humans are inherently bad and are expected to underdeliver and not be generous to others without this benefit ing their agenda. Hence, if in teaching there is no clear social contract but vaque and general expectations that cannot asses deepest commitment to seeing others succeed at higher standards but a mere commitment to not prevent this by eye catching or basic omissions, the question above is valid.