I don't mean to sound like a hater to other's opinions, but it's true.. some people are being way too harsh and way too picky! Rowling is giving us new information, we should all be happy!!!! 
 I love Minerva so much more than I already did! 
 Lupin just made me sad all over again. 
 Trelawney was vague but at least Rowling explained why she wasn't so sure. 
 Last but not least, Silvanus Kettleburn, uh hello! That was an awesome little treat! Especially how (view spoiler)[ he helped in the Battle of Hogwarts the best he could (hide spoiler)] That's a true diamond in the rough hero, if I do say so myself. :) 
 All in all, we shouldn't be too harsh on these Pottermore books. They're fun, we get to discover more of the world we all love, and it brings us back to home just one more time than before.