Yeah, Konkon is totally separated from UFA now so she has no place in these things anymore.
It'd be like if they included Ishiguro Aya for no reason.
The ranking poll is specifically to answer the question of who seems like they would become the #1 hostess in Ginza.
Hostesses are found in
hostess clubs, which wiki is describing as like strip clubs "without dancing or nudity".
With that in mind, any of the members under 20 wouldn't be good options to have on that poll.