Main reason to divert this train could actually be to encourage upcoming private trains. If you see my attachments :
1. They have proposed TCTB NDLS via SC (e2e better slot and connectivity for SL n non premium train )
2. There are 3 more trains from TCTB to GKP/PNBE/Prayagraj (23.15 slot and evening slot from TCTB towards SC/KCG and one early morning arrival at TCTB at 7am so will be perfect overnight from SC/KCG)
I...
more... think considering these factors and also north karnataka - IR/SWR diverted ksk via BAY and UBL