According to this Tweet response to a fan, J.K. Rowling has confirmed that the script for the second Fantastic Beasts and Where to Find Them film is completed and ready for filming this summer. Naturally, this has created a lot of excitement and speculation on her Twitter page which you can read here.
Personally, I’m still gobsmacked that Rowling added an older brother for Newt Scamander in the second film which was announced here by Pottermore. I guess I missed the reference to Theseus Scamander in the first film. He was mentioned as a war hero, recognized by the Representatives of the International Confederation of Wizards. Just the same, he is still one of Rowling’s little mysteries that apparently will be elaborated in the second film.