Kamayani Express - Late आना है काम तुम्हारा लेकिन मैं फिर भी हूँ तुम्हारा दीवाना - Aman

This is nothing new. 2 tier non-A/C sleeper coaches were used for a long time on IR, well into the 80's.
They were discontinued as the 3-tier design was found to be better for increasing passenger capacity and increasing the revenue per coach.
Putting back the middle berth is a relatively trivial task. Coaches which will be brought back into service will mostly be given back their middle berths.

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