Most probably no... Plus have they ever cut a promo on kartik because promo always contains key characters. Considering kartik was a potential love interest of yuvika, they should've cut a promo for him.
Also, vanshaj is a family drama who's core plot revolve around Mahajan family. Hence, yuvika's love interest should not hold that much importance. If yes, then that person has to connected with Mahajan family. So vidur's son being ML makes sense.
Still we have to wait and watch.
I don't think Yuvika's love interest would be very important
If it would be then they need to have child of some rival business house like Draupadi
But Vidur mentioned his son in first episode itself so I guess he can be an important person
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