It would have made more sense if the Fox news presenter had made reference to Mecca instead of Tehran. It is clear that A-5 can hit Mecca and Medina well within its range. Even though Mecca was just on the very edge of Agni-III's range, Agni-V can easily cover the entire middle-east.
There are many Islamists in Pakistan who keep advocating nuclear annihilation of 'Hindu India', who are unconcerned about the retaliatory destruction of their own country. Their contention is that Indian civilization will be finished, even if it means Pakistan is destroyed, Islam will survive. I wonder how they will react if they knew that couple of nuclear MIRV'ed A-5's will be pointing at Mecca and Medina.
This kind of response has been advocated by a few ultra-conservative American's and Israeli's too before, to any jihadi terrorist attacks involving nuclear weapons, in future.
I don't think India will make an official announcement of it, if in case it actually puts Mecca in the list of target locations.
India doesn't see any conflict/war in religious perspective. But Pakistan does. Does ghazwa-e-Hind ring a bell? There is an influential Islamist fringe in Pakistan who actively adocates nuking India. Pakistan even calls it nuclear devices as the 'Islamic Bomb'. Nuclear blackmail and talking about nukes at a drop of a hat has been Pakistan's policy since they went nuclear. Remember Kargil, when Musharrafs men had started assembling the nuclear devices, even though the conflict was a very localised one. India will need an effective counter-strategy to this kind of suicidal, religiously motivated individuals/groups and targeting their places of religious importance could be one of them. I'm not advocating that it should be done, but A-5 does open one more possibility/capability.