They’re not done yet. Just announcing (and the verge reporting on it).
Their announcement (here) is quite forceful though, interestingly. The article described it as a manifesto.
See also a recent post here about their survey on integrating activity pub: https://lemmy.ml/post/14734757
What is the question, exactly?
I assume your Ghost account will become a Fedi account and your articles will be automatically shared with headlines and links to the article, along with federated boosts, likes and comments.