It’s less impressive than it sounds. In his “hesder” program, Jewish boys serve in an army that drafts females, which is assur by all the gedolim even if they don’t sing. It’s no great heroism for him to resign from the program while leaving the bachurim in. Also, the army keeps typical RZ loophole Yiddishkeit in all other things (Shabbos, kashrus, davening etc.) and where is his protest over that?
