Well quite frankly Indian media is just guessing here.
Lt Gen Zubair Hayat is from the artillery and the serving CGS. As a three-star general, he was previously posted as director general of the Strategic Plans Division (SPD), which is the secretariat of the NCA; and corps commander Bahawalpur. This makes him an ideal choice for the post of CJCSC, who has an almost exclusive jurisdiction over nuclear forces and assets.
It is very rare for someone posted at the SPD to go back to the army. Therefore, many see in his return to the GHQ within a year and half of his transfer to the SPD an ambitious rise to a four-star position.
His postings as CGS and DG SPD afforded him an opportunity to work very closely with PM Sharif and Finance Minister Ishaq Dar.
During his tenure as a major general, he was general officer commanding (GOC) Sialkot and later headed the Staff Duties (SD) Directorate, whose personnel are commonly known in the army as ‘paper tigers’. His stay at the directorate and his earlier posting as principal staff officer to the army chief brought him closer to Gen Kayani, and he is generally seen as Gen Kayani’s protégé.
However, his primary shortcoming is that he has never served in a conflict zone.
Some of those who worked with him describe him as “workaholic” and a “vociferous reader”.
He is also said to have a very sharp memory.
Gen Zubair is a second generation officer. His father retired as a major general, while two of his brothers are generals: Pakistan Ordnance Factories Wah Chairman Lt Gen Omar Hayat and Inter-Services Intelligence DG (Analysis) Maj Gen Ahmad Mahmood Hayat.
http://www.dawn.com/news/1277442