Manyata hates Uday at the moment because she believes Uday has killed Akash, and that's why she is being so hostile towards Uday..
However if Akash turn out to be alive, she will realise that she was being horrible to Uday for no reason, and might regret her actions..
She doesn't even seem to care that that Uday lied to her, and kind of betrayed her.. All she cares about at the moment is Akash's life.. Uday's betrayal is tiny compared to him killing Akash.
So that means if Akash is alive, there will be nothing left for her to hate Uday for as she would probably get over his betrayal easily, the only thing holding her back is Akash.
Hope I made sense.