In this case, I'm thinking about sequels to, for want of a better word, classic novels, written not by the author of the classic novel, but by someone 'commissioned' by the estate. It's Winnie-the-Pooh who is up for the treatment this time (see here).
And does it make it better that it's for charity?
I suppose in a practical sense, it's not really a bad thing. Though it is far too easy to write a parody of Milne's style without capturing the actual wit. We shall see. And if we don't want to see... well, no one is making us read or even acknowledge the sequel.
And, after all, I wasn't that upset about Eoin Colfer writing a sequel to the Hitchhiker books.