Well, weren't there persistent rumours of PAF getting J-10s which were largely dismissed before they actually started being delivered? So it will not be that surprising to see J-35 delivered as well sometime in the near future. Point being, it would be wise not to dismiss and deride rumours such as this so easily.
Same with Jf-17 Azerbaijan sales that eventually turned out to be true. The usual suspects ran with it for months prior to official confirmation.
But the point with those were more headline rumours, birds eye view of things.
This is a specific plane, a single unit. So, we have to discern what is being talked about.
Can we say with any degree of confidence that this specific unit is for PAF? I would say, absolutely no we cannot.
Can we say at some point in future, PAF will have J-35, I think that falls in realm of possibility.
So let us not confuse two similar yet very different points of discussion. Lets also focus on the aircraft
This is in addition to the point raised by Dieno.