Rambam hilchos Talmud Torah 1:13.
Considering the Beis Yaakov movement teaches Written Torah and Halacha, one could assume that the Moetzes is fine with the tiflus concern.
They have the heter of learning Torah Sh'biksav which is mentioned there, (as muter bdieved not lketchila), as well as for dinim which is nogea for women.
Torah shel bal peh there is no heter, so they wern't part of this Siyum Hashas for learning themselves, but for enabling their husbands.
And this concept of praising them for enabling their husbands Is a gemura in Bruchos 17 "נשים במאי זכיין"