Gavra
Well said, my first reaction was like you, though I asked Popa directly to clarify.
To me it sounded like another facet of daas torah namely accepting anything from a rosh yeshiva wether it makes sense or not.
The idea that a kesuba which provideds for a woman in the event of divorce stregthens marriage while a prenup which allows a “divorced” (i.e. civilly or practicly) woman to remarry weakens marriage is not something anybody rational would accept. But if the “rosh Yeshiva” said it it becomes Torah misiani.
again though to be fair, perhaps it makes sense but requires further explanation