I don't think Vivaan will hide Imli.
But i feel he is still in connection with mystery lady.
The sudden changes in him is fishy..
May be mystery lady give him new task to increase problems between Sukor.
So he using childhood friendship and faking his support to Chakor.
The way he told mystery women on phone that he will protect Sukor was the first and may be to gain their trust.
And after Sooraj's dialogue about Sukor are not childhood friends give him the hint that Sooraj not liking the bond he and Chakor sharing.
So he puropsely trying to revive childhood friendship with her.
And when gas operation going on,he not satisfied with it
So it's obvious he will try his part alone and he knows missing link with mystery women will lead to miss him in reaching to Imli.
Now may be mystery women try to mislead Sooraj like Vivaan still after their life and Vivaan will do something which make Sooraj believe Vivaan tried to kill Chakor but Sooraj can't prove it and Vivaan will act innocent and Chakor don't believe it that Vivaan tried to kill her.
And with challenge going on between Sukor,Chakor may be able to prove Imli alive but can't able to catch her.
And Imli might try to do something with Saanvi or even try to kidnap her.
Ragini will play above of all four and try to mislead everyone.
Which lead to lot of confusions and MUS.
So when Sooraj finally realised Imli alive,the next problem will be their trust on Vivaan.
Imli will play hide and seek for sometime.
I may be wrong but i feel this can be also possible.