It turns out the answer is no, although both batteries are in the right ear cup, and ifixit never do figure if there is a counterweight in the other ear. There’s just a gap.
And yeah… adding that weight was a crappy move and very un-apple IMHO. Their products should stand on their own and not require gimmicks like that. Having said that, this is Beats. Analysis showed that their products cost as little as $18 to make (including parts and assembly) - talk about cheap overpriced crap. The other few hundred dollars per set is marketing, distribution and profit. Shows what celebrity endorsements can get you.