It's just because of the change in departure time from Banaras (Manduadih) before the departure time was 19:40 and now departure time is 22:15 and almost reaches New Delhi at the same time as the earlier schedule.
I have also faced the same problem, NE Railway should at least add On-board Catering service for morning tea and for 12560 as it leaves New Delhi at 20:05.