Yes, if this had been real life, I'd say forgiveness is plausible, especially given Mirza's attitude and Jalal's own new understanding of love, but a grand celebration would be unlikely.
However, who knows, this is TV and this Jalal is a man of whims. :)
He just might decide that what really matters is love and bringing happiness to those who love (and those he loves, for example Jodha, Mirza, HB, etc).
Remember his speech in Mathura, while standing up for the widow? It wasn't just about justice or against excessive punishment. He was positively promoting love and, important in the present context, the superiority of true love over petty objections based on traditional values.
He can easily brush aside the fact that Shivani marries a commoner. If that's anyone's problem, it is Bharmal's and the rest of Amer clan. :) Anyway, Jalal's own sister BB married a commoner SD, but instead of looking down upon her, SD's rank got raised. [In this respect, and a few others, Mughal culture was more dynamic, adaptive, and practical than rusted out aspects of Hindu / Rajput ways where many things got frozen at birth. Of course, as Akbar recognized himself, in a few other respects Mughals could use an infusion of native Indian values.]
As for Shivani lying, that can be blamed on MA. As for their running away, mazboori under the circumstances; anyone can see that.
Also, both Jalal and Jodha are big time "rescuers" by personality and temperament. He might decide to organize a jashn for Shivani and Tejwant just because those two are not in a position to do it for themselves and nobody else will help them. And, let's not forget that this would please not only his begum Jodha but also his brother Mirza! What's there not to like about this jashn?
All in all, I am not saying that the story will definitely take this trail, but I do see a trail.