One of the silliest nominations in Tony history. My guess is that they wanted to nominate Lauri Peters, whose role as Liesl was substantial enough to warrant it, but then decided to include the six others as an afterthought or whatever. There was no chance in hell that the 7 would actually win since Patricia Neway as the Mother Abbess was heavily favored.
The Tony nominating committee was not trying to make any type of statement by including two male actors William Snowden and Joseph Stewart in this group nomination for best featured musical actress. I don't think their action should be regarded as a precedent, just a frivolous decision and an example of poor judgment. Just IMO, of course.