The two strongest opponents for India were:
1) Pakistan. Got utterly destroyed, with their bowlers taking 2 wkts for 404 runs. So beating Pakistan was definitely not a fluke.
2) Bangladesh. Came very close to beating India in the final. However was utterly destroyed by India in the earlier game. So the final victory for India was not a fluke, which is something unexpected. If Bangladesh would have beaten India, then that victory could have been called a fluke because they were thoroughly beaten by India in the earlier game.
3) Pakistan's CT final win is called a fluke, and given that they were quite thoroughly beaten by India the previous game, it may indeed have been a fluke. However, I do not think Pakistan's victory was a fluke, given the wide margin by which they won.