He did not choose anyone really for a life partner!
He did choose Tannu as girlfriend in KB season 1. But then Daadi pushed him to marry and he thought Tannu could be that girl half heartedly.
Pragya has never been his 'love at first sight' choice before or now. He did grow to appreciate Pragya.. I feel he would not have had a choice to say No to her morally when she has lost so much for their marriage!!
Now it's not that he is choosing Tannu. Aaliyah has caught his weaknesses here. Like he cares about his career, Tannu's or any woman's respect, he cares about elders.. so they have caught him under those emotions and forcing him to marry Tannu. Just like Aalu forced him to marry Pragya, she is forcing him to marry Tannu now.
I don't think Pragya should try to put herself as his choice here. If anything she should try to help his ML and because Tannu is a criminal and he doesn't know and because he drove the car that was meant to kill her..Pragya would have a moral responsibility here..
So I expect her to help him with his memory indirectly with a doctor and I also hope that she can put Taaliyah behind the bars for their crimes.
As per Abhi, he has accepted Pragya to be his wife in the end of preggy track. Once he gets his memory he will go back to her. It's not about love here really.. I haven't seen true love from anyone to anyone in the big picture.. some are blinded by selfishness, some are into symbols and some are misguided.. it's all about marriage and commitment!