I'm not a neurologist but I believe that not all learning is the same. In this case they were specifically learning spatial mapping (and possibly manipulation and reasoning). The study doesn't say anything about linguistic learning, which happens in a different part of the brain.
I would imagine only if you were fluent in it. I bet these cabbies have to lice And breathe this information. You need not just a pile of facts, but the bigger picture: it has to be instinctive.