Yes - like all the other Christian ministers - mostly Methodists, Baptists and Congregationalists, this being noncomformist Wales - who in the last 150 years or so have accepted the same honorary title as Rowan Williams did for their Welsh language poetry. As anybody who takes the trouble to check the background will discover, the Welsh cultural revival movement in the 19th century (largely led, as it happens, by Christian ministers) chose in a fit of whimsical acknowledgement of that culture's ancient origins to bestow quaint titles such as Bard and Druid on the various awards and honours which it established, to be bestowed at the various annual eisteddfodau (festivals of Welsh music and poetry). It has nothing, but nothing, to do with paganism.
Williams is a published poet in the Welsh language. He has many faults, but dabbling with paganism is not one of them. His only error in this instance was naivete in failing to anticipate that acceptance would be misinterpreted on the way it has been by those outside Wales who are ignorant of this background.
Sorry, but the rewriting of doctrine speaks for itself. Nor does it mean that the other druids (documentation?) are any different.