Sahiba won't be able to keep him away from the child, in my opinion. Simran poses a bigger challenge for him. When Akir finds out the truth, he might become furious with Sahiba and lean towards Angad, but Simran will make sure Angad doesn't put Akir first.
The problem with daily soap heroines is that they tend to go for the messier route. Telling your child what the biological father did to you will make him hate the father as well. Even in Yeh Rishta, where Naira was far more determined and staged her death in order to punish Kartik, she never told Kairav why she was angry with Kartik. Yes, I find it irritating to even make comparisons to Sahan because Kaira is one on-screen relationship that nailed every single cliche. By omitting the entire truth, the female characters dig their own grave. In all honesty, Sahiba can reveal everything that Angad did to her, on a superficial level because Akir is still very young, and Angad will never be able to take her kid away from her. Sai purposefully kept Savi away in Ghum, but she did not speak against her in laws. You take the simple route when you don't like someone, but female leads will always take the most convoluted path.
Angad is the cause of his own suffering. He had seven years to get married and have a baby. But rather than thinking about the existence of a lady he claimed to love, he chose to cry over the death of someone he had known for less than a week. With all the money, he ought to have joined a counseling session that would have aided him in healing if he couldn't cope with grief. Rather, he focused his energies in indulging Simran's tantrums.