I think this matter is being exaggerated, when the World Cup was held on Indian soil, the Pakistan team went to India and played the World Cup, so if the protocol is given, what is the problem with Indian cricketers playing for Pakistan? The problem is that the ICC decides exactly as India says, if there was another team in India's place, maybe the ICC would have directly informed that team that if you have a problem, withdraw your name from the World Cup, but where India is, the ICC is not able to interfere much. If the future Champions Trophy matches are held in Pakistan, if India's matches are given as per their wish, it will have a bad impact on other teams. Let's see what the ICC decides in this case.
Well.. I don't think that you understand the issue well enough. The BCCI doesn't care whether Pakistan team visits India or not. Even if Pakistan is not there in the world cup, there will be hardly any financial implications for the ICC. On the other hand, in case the Indian team refuses to take part in any of the ICC tournaments, then 80% of the revenue from that tournament is gone. And this is where it gets tricky. I know that it is unfair to Pakistan, but this is how revenue distribution works in international cricket.