I really question why Shcherbakova would go. She's been having health issues basically all season long and both at the Worlds and the Channel 1 Trophy she looked rough (at the Cup she had tapes all around her knees). She fought through it to become WC - understandably - but instead of taking time to recover, she'll have to continue train fully competitively until mid-April. Then show season (in Russia at least) will start, which is a little less demanding, sure, but still requires readiness. Then the pre-Olympic training camp in Novogorsk. When's that girl gonna get the break she really, really needs? I'm sure she wants to go and WTT is a fun competition with nice prize money but this is the year before the Olympics and it's really not smart to risk your health like that. It would be very sad if this backfires on her - she's basically Medvedeva's age going into next season and I think we all remember that the first injuries from overtraining showed up for her at that time. And she, unlike Shcherbakova, didn't have to deal with pneumonia a mere months before.
Send Nugumanova, if Kostornaya is still recovering. It's not a serious event and she'd deserve some international exposure.