In regards to the promo for the next episode, Sana is seen breaking the decoration for Sid's team. I'm going to have hope here and say she didn't decide to flip last minute. If the situation is how it's shown then Asim has decided to make a new group so there is no point in making Sid's team win because they won't choose her or Sid as a new captain. If stuff is still bad between Sid and Asim then it's better to have someone from Paras team be a captain.
Or she just didn't like the decorations