^^ It's called home advantage so it does play some part for the home team but anything could happen in the knockout stage. 1 bad day or 1 bad hour and you are out so no team can take their opponent lightly and it applies to every semi finalist, including the host nation.

When it comes to conspiracy theories then look at this way. Indian pitches are famous for spin, which could have played into India's hand because India has quality spinners who can bat down the order(for ex: Axar or Sunder) but so far we haven't seen any rank turner, even Chepuk pitch didn't offer much assistance to spinners and quite surprisingly Pacers are dominating the bowling department in this edition.