I'm having the sneaking suspicion lately that the Timurids will be in VI. Or at least more likely than the Mughals. Reasons:
1. We don't have a civ filling out the "stans" between Persia, Scythia, and India.
2. VI seems to be focusing, even moreso than V, on representing larger cultural paradigms with civs (which the Gurkhani definitely were the largest influencer of the region), and less influential empires with city states (like Kabul repping the Durrani empire).
3. Where cultural paradigms have survived multiple polities (as here with the Timurids and Mughals), the devs have done one of two things. For long enduring cultures, they have included multiple leaders to represent different polities and the change over time. For smaller patches of history, they chose the largest cultural figure to lead the civ, either as representing the height of the civ (Cyrus, Genghis) or it's origination (Kupe, Dido). Here, we clearly have Timur and Akbar/Nur Jahan as frontrunners, but as far as being a cultural hero Timur satisfies both a high point and an origin point for the Gurkhani paradigm. Put simply, he serves the same function as representing the prototypical beginnings for the Mughals in the same way that Dido represents Carthage. He would be a two-fer.
4. Back on the subject of Cyrus, yes I realize that Persia lasted a long time and still will likely only have one leader, but there seems to be a reason why the devs made it DLC and not part of the main game. And I think that reason is, unlike Arabia or China which have many clear alternatives for leaders, Persia has the peculiar situation of having occupied similarly defined territory as several completely different empires, such as Macedon and coincidentally the Timurid empire. In fact I believe this is partly why Alexander was split from Greece, so that he could function as a quasi-alternate leader for the same region as Cyrus. I could see the developers completing the trifecta by including a Turkic leader from the Eastern side of the region.
5. Timur's starting location at Samarkand is a little less cramped than wherever Akbar or Nur Jahan would start. Since the whole point of including the Gurkhani would be to fill out Afghanistan and Pakistan, we would have to stretch to justify either Mughal leader starting in Lahore instead of Agra. But this isn't even an issue with Tamerlane if he starts in Uzbekistan.
Of course, many analagous reasons could be made for Attila serving as a quasi-alternate leader extension of Scythia. And he would likely serve a very similar mechanical niche. So I don't know. It remains to be seen I guess.