Eh, I was reasonably convinced by the source. As for HP, think about it; the original film series will be 30-35+ years old by the time this park gets 'round to incorporating the franchise, if it does. Whatever one's personal opinions, the upcoming TV series is going to massive, and define what Harry Potter means to entire generations. It'll be firmly into the fourth or fifth season by the time groundwork begins, if true, nearing the finale by opening. By contrast, the film series' cast will have aged out to incorporate them into any elements; it's therefore perfectly logical to suspect that's the direction they'll go - using the new cast, art direction etc.
There were old rumours about Game of Thrones / HotD too, though I think they've been quiet for a while (perhaps post-securing LOTR? Who knows... ).