This would make sense acc. to the Rema in 276 #2 where he first says Ameira L’acum is Mutter even by a Melacha Gemura B’mokom Mitzva and then says be Machmir unless it’s a case of Tzorech Godol. You see clearly he differentiated between the two!
So you’re conceding that not having cholent is not a tzorech gadol, only a d’var mitzvah, and that it’s therefore assur even according to the R’ma?