Back to the original question about the newbuilding, officially registered as ABLE ONE OF WHITBY, currently cruising in Croatia, with owner still listed as Andrew Whalley.
As for "why" of the newbuilding, the answer lies in this article on the 2009 hull survey:
https://derij.co.uk/news/marine-eng/27-65-tug-survey
It concluded that the intended lengthening involved in the yacht conversion would be complex, and expensive, whereas a near replica would not only provide the additional length but could be made a little more beamy:
original: 21.3oa x 5.9m
new: 26.75oa x 7m