Well it doesn't matter if this alleged S-400 deployment is true or false.
1) First of all he seems to think that the S-400s are the only Chinese SAM system that could threaten the IAF. What about all those HQ-9s and its medium and short ranged brethren already deployed in the area? He seems to forget that the HQ-9s are paired with superior AESA radars than the S-400s PESA radars. And while HQ-9s have shorter max range than S-400s, they are deployed at substantially high altitudes. So the max range could be further than on paper. And the PLA have practiced using them at these altitudes. Off course, the S-400s could perform better there, but Shukla is giving no credit to the other Chinese SAMs in the area. A big strategic miscalculation.
Correct ! There are other even more strategic miscalculations being propagated by so called experts. While Shukla is at least giving credit to the S-400 threat there are dozens of so called "experts " ( and we don't need to reference their garbage here) who are discounting the threat from PLA SAMS, AAA, and even MANPADS entirely. These experts claim that the PLA doctrine of layered ground based defense is based on dated Soviet tactics commonly adopted by Arab air defenses (with not much success ) against the Israelis in the Middle East conflicts.