/u/Mr_D-N-A does make a good point. There's a huge issue of rivalry here; namely, Spielberg is the best mate of the grandaddy of the Star Wars franchise. Kathleen Kennedy, who now runs Lucasfilm, has worked with Spielberg on numerous occasions. The decision to park right in the favoured spot of Spielberg's long-gestating Ready Player One adaptation is a little harsh, considering the former comraderie between those involved. It's entirely possible that Kathleen placed a well-intentioned phonecall to Dreamworks to call a spade a spade and say it was all in good-humoured, business-minded jest - but don't be surprised if Ready Player One loses that release date stare-down and budges to slightly earlier or later in the year.