Marvel EIC teased an upcoming announcement regarding Greg Pak in his latest My Cup O’ Joe column:

Spidey616 asks: It can’t be true that writer Greg Pak is leaving Skaar: Son of Hulk with issue #13 when the title is retitled simply Son of Hulk! Is it? Is this truly the end of Skaar for Pak, or is it far from over?
JQ: Rest easy Pak fans! There’s a MAJOR MAJOR announcement coming up for Hulk and Greg Pak that has a LOT to do with Hulk #600! (See how important that single issue is going to be?!)