First of all, VB doesn't need any special track, lots of VB running on 110 km/hr and even running on single track. Secondly, you should better come to Gorakhpur and see the number of daily passenger, before saying that GKP doesn't deserve premium train. Gorakhpur Originating 57 train, which is still higher then LKO, CNB, BSB and PRYJ. Railway is planning to run Mini VB, so there's a possibility of VB between GKP and CNB.