I was about to make a thread about this news, and I'm happy that Bitcointalk search feature was helpful for once, and I found this thread before making another one.
But the way I understand it, Do Kwon does NOT want to be extradited neither to the USA nor to South Korea, so this decision was in his favour, actually.
From the article you shared:
Following a series of appeals by Do Kwon against extradition decisions favoring the U.S. and South Korea, the document notes that the Montenegro Appeals Court identified significant procedural breaches in the handling of extradition requests.
So he's against extradition, and the extradition to the US was formally stopped on the grounds of inconsistency of where he should be extradited (to the US or to South Korea).