The fans want more, she is giving them more. What's the problem?
Yea, and she never claimed she would never visit the Universe again, she only said Harry's story would be done, and in fact, near the end of the Septology, she did say it was possible she would revisit the Universe, but, she wanted to try other Genres first, and she has now Published 2 very different books not in the HP Universe, in two different genres/Sub-genres
One Day I hope to be the Man my Cat thinks I am
Where are we going? And why are we in this Handbasket?