I think the reason why JJKN storyline headed to Nainital is because she will end up working in that orphanage where Rohit/Ronit is staying. She will be "The Teacher" there so she can stay close to Rohit/Ronit. I feel like the story will go toward "kuch kuch hota hai style", since we all know how much t&D love the srk movie style in their show, it's a possibility.
They will make Armaan suffer for Jassi some more. To make him feel that he will die without her, become devdas bluh blub bluh. Ofcourse along the way they will bring more characters that will fall madly in love with Jassi. It's like Purab, Armaan, Raj, Parvatlaal??, CJ???(he either loves Jassi or Purab, don't know who more😕) isn't enough. Sometimes I feel like they should change the title to "everybody loves Jassi - sevaaye Mallika & Ila".