As long as it retains its explanatory power, i.e. as long as the legacies of colonialism persist, I think the term postcolonial will remain in use. I understand the backlash against it, but in certain contexts, it continues to make sense. Some other phrases, "Third World," for instance, are completely passe, but not postcolonial.
I think you might be on to something here. The term postcolonial seems to recognize the exploitation of imperialism. However, the “post” is also significant. It means moving on beyond something. We cannot ignore our imperial past. It is part of the world’s common history. East meets west is not completely out of date either. There are still immense cultural differences, even though the world is getting smaller.