I am a little unsure whether you meant 'you' as in me or was it a generalisation, but I am having a bad day and this discussion has been the only positive highlight, so I am going to continue :)
I fully agree, the only person who will suffer is Viraj. And unlike the previous (and current, if we count Sonalika/Komolika's return) third angles, Viraj hasn't contributed to this mess. Anurag brought a marriage proposal for him, he heard about Prerna's situation, and he decided that if life us giving him a second chance at a family, he is going to take it. It was Prerna's responsibility to decline, and she couldn't do that. Even now, she can just take him to the side and clear things. She doesn't need to disclose everything if she feels she can't trust him (and she shouldn't trust him, she doesn't know him that well). She can simply say that she doesn't want to move on and she had only agreed to the proposal because her mother is panicking about her future. She should tell him that she will never be able to be his wife, that she will never be able to move on. No shame in that, that's her love and her happiness and that's her choice. And I want her to do the needful. A decent guy like Viraj doesn't deserve the humiliation that is coming his way. The man has already lost a wife, he has already lost a child! Keeping him in the dark will be a hard blow. I want her to be selfish, but I don't want a Prerna who will purposely hurt someone because she is too much of a coward to do otherwise.
She is already doing everything possible to hint at her feelings for Anurag, she is already going against her mother's wishes, she can call off this marriage and free Viraj from this tangle of relationships.
And she should do something about Komolika/Sonalika. Even if Anurag's memory comes back, he won't know about Komo's truth. She needs to be the one to tell him. Even now, she can tell Moloy, or Anupam, or the Sharmas. But no, Prerna Sharma is not allowed proper character development. But that's a discussion for another day. For now, I hope she takes control of the situation instead of dancing with Anurag. And in a way, that too will be for her own happiness. Prerna should be selfish and she should end this farce of a marriage alliance.
Everyone deserves better.
Again, I am sorry if I keep talking nonsense, I just need something to divert my mind from rl issues.