I think that Swapnil will return in Parivaar.
This will be the perfect time for him to come back. He can claim that Radha is DR and she, being the dutiful daughter she is, she will bind and save his parivaar too.
Remember Faisal's article? He said that "I am to be paired opposite Radha. There's a major twist after 15 episodes and that's where the story begins to pick up"
It's been around 15 episodes since he came in. So maybe this is what he meant.
Now he will come back and the track will change direction (again)
Yuks