While recently attending a graveside l'vayah and burial, the Rabbi who officiated started the service completely omitting the b'rachah -
"Baruch ... Asher Yotzar eschem Baddin"
Usually, when I conduct a burial I make it a point to either recite it myself out loud - to be Motzi anyone who has not been to a cemetery within 30 days; or at least to have another person recite it out loud.
Even if the Rav has been at a cemetery it seems that he could still recite the b'rachah for the many who need to be yotzei who can't or won't say it on their own. Alternatively, he might designate an alternate who has not been there during the past 30 days.