Mike Laidlaw, a director who was involved with games like Mass Effect, Jade Empire, and most famously the Dragon Age franchise. He was creative director for Dragon Age: Inquisition. He never gave a reason as to why he left aside from that it was time to move on.
David Gaider, creator and former lead writer of the Dragon Age franchise also left BioWare in early 2016 to form his company, Beamdog Studios with other ex BioWare members.
As for the future of Dragon Age, a fourth title has been confirmed to be in development. Aside from that, nothing else is known of the game.