The only way for original titans ages to make (some) sense in the post-Crisis continuity is for them to be 27.
In the New 52, Dick is between 21/22. It's assumed the other Titans have the same age, as they did before, so that's it.
The ten years that were stolen from the DC universe were probably not a big chunk of time, but a feel seconds here, a few seconds there, all of those tiny bits containing important events.