Pakistan has every right to say we wont travel to India. Around the start of 2010s if we had said security reason its understandable but now we cant say that as Aussies, English and others have travelled without an issue.
The only reason India is not travelling to Pak and asking for Asia Cup games in neutral venues is political. So Pakistan can say the same about travelling to India for WC. They can ask for all their matches to be played in SL or somewhere then we might have to allow the same.
Like the saying goes You get what you give thats the way the world works. If you're happy with it or not