It may be noted that last rly budget did not announce double decker yuva trains. It announced both a) starting of Yuva trains (with a provision to provide airconditioned seated accomodation) and b) starting of double decker AC trains for inter-city travel.
Budget excerpts :-
Air conditioned double decker coaches for inter-city travel :
"...the house will be happy to...
more... know that like double decker buses we
are taking the novel initiative of introducing high capacity air conditioned
double-decker coaches, for intercity travel. These will have superior riding
quality and comfort".