Dictionaries can give "generally accepted pronunciations", but these don't necessarily coincide with the variation in how people talk, especially regional variations, even within countries. (eg Geordies!) Nor for that matter do they keep tag of the way in which speech varies over the years.

There's always a tension of opinion as to whether dictionaries should be primarily descriptive or prescriptive - should they record how we do speak, or instruct us as to how we should speak.

The general consensus, in the UK anyway, seems to be that the emphasis should be on the former.