Brothers with shaved heads aren't allowed to give talks at circuit or district Assemblies as per the WTBTS instructions for recommending speakers although they do allow a degree of discretion... Absolutely no beards allowed though.
"if there are questions about his dress or grooming has he responded to counsel? Discernment should be exercised when determining this matter. For instance, perhaps a close shaven hair-cut is related to a health matter or the brother may be balding or this has been his hairstyle for many years and is not a cause of concern. "