Where is the Harry Potter Encyclopedia?

Today is a magical day for Harry Potter fans: it is J.K. Rowling’s birthday, Harry Potter’s birthday, and the twelfth anniversary of the release of Harry Potter and the Deathly Hallows, the final book in the series.

Things have changed a lot since 2007, but one thing has not changed. The fans desperately want a comprehensive encyclopedia of Harry’s world. This eagerly anticipated addition to the Wizarding World has been promised and retracted more times than I care to remember, and waiting for it while seeing so many other new additions to the Harry Potter universe that nobody asked for (Cursed Child, Fantastic Beasts) has been utterly exhausting. Pottermore was an interesting and appreciated way for JKR to offer fans more of the information that we crave, but it has never been the comprehensive volume we’ve been wanting for years. On the behalf of every Harry Potter fan, as well as the charities that would benefit from the promised donation of the resulting proceeds, please, finally, give us the encyclopedia.

I've waited twelve years, I'm not going to wait much longer.

—Sirius Black