Do wolves really eat their cubs?

No! They take care of them until they're the age where they can live on their own, then they leave them.

The above is Untrue, like Most Mammals Wolves will eat their own young depending on Pack Size and food availability, and to add a further note wolves are a Social Animal and do not leave the Pack until they are too old to hunt, then they simply wonder off alone finding a place to take their final rest.