User blog comment:MeerkatQueen/List of VOCALOIDs with "br" phonetics/@comment-6433273-20190514162511/@comment-6433273-20190514170313

Actually, none of Yukari's VBs have them (including V3, likely because of the external samples)

But still, if what you say about Iroha having them is true, then I just find it a bit more baffling that Kiyoteru doesn't have them. Still, as you said, br phonemes are usually unnecessary at this point.