No, it is not true. Not over here, at least.
The requirement on Australian operations is for carriage of survival
equipment for sustaining life appropriate to the area being overflown, in two specific cases - designated remote areas, and flights where carriage of life raft is required. No emergency rations, no emergency water supplies (except a limited amount packed in with Life Raft emergency equipment).
In fact, if there is a catering stuff up, we often leave without enough food for the advertised in-flight service!
Food is way down on the list of priorities. Survival experts will tell you that people can survive for almost 30 days without food. Far more important to be attending to injuries, sheltering from the elements, etc.
If you are interested, take a look at our
Regulations for survival equipment. No rations.