If IR wants to make this VB run as a kind of RSA version meaning it is meant more for passengers travelling b/w GKP and LKO and then LKO and ALD, then it makes sense; but combined it makes nothing.
Either case, I agree that LKO-PPTA would have made a better case. An ICE runs on that route but it has shit timings [arrives at LJN post 2 am in night and gets rescheduled frequently. It was as late as nine hours few days before]. Lucknow and Patna can do with a...
more... faster VB, be it via LKO-SLN-BSB-MGS-PNBE route or via LKO-GKP-PPTA route. I think the latter has slower mps but is slightly shorter but I could be wrong. Either case, an eight coacher demand can easily be fulfilled on Lucknow-Patna sector, especially if Varanasi comes into the middle.