I don't think Razia will let the sisters know about the past. That would be a little too early for soap standards. If she had to tell, she would have revealed it to Seher, no? Instead she PAID Seher. I can't come up with a suitable theory either ( which might perhaps have something to do with the gaps of logic in the show? ). Either ways, while the swap will bring some scenes worth watching, it is too mainstream and I would love for the CVs to come up with something different. I'll sit through whatever comes anyway.
Oh and about Sehaan. Tbh, the story was tooo rushed and illogical specially for Rehaan's feelings to crop so easily and quickly for her. Uh-huh. I'll admit though once I throw away logic and Rehan's past attraction, I enjoy their cute chemistry.
I think Rehan falling for Seher serves revenge. What worse comeback for Billi than to have her son love the very daughter of her enemies, the people she murdered. Plus, Seher's downfall means killing her son's happiness. So its a loss for her from every side. Or at least thats what I think.
And your right, while I detest all the side tracks, they need a closure, I feel so... whats the word? OCD-ish? about all those extra characters who jammed the screen previously and are now nowhere to be seen. Closing them all and having ARI's sisters for example make an appearance now and then would put me at ease.
OMG. This turned into a rant-fest. I apologize, it just all came out.