But if they listen to them it might cause them to become apikorsim through kfira in the RaMBaM’s 14th and 15th ikkarim.
Ani maamin b’emuna shleima that any yeshiva not of the approved type cannot possibly produce any Torah.
Ani maamin b’emuna shleima that any shiur given consistently in one language is kfira and has a din sefer torah shekasvo apikorus.