The newly-announced Mission: Impossible – The Final Reckoning will indeed be final. It's been a good run, even if I couldn't tell you what actually happens in any of the movies. You don't show up to Mission: Impossible for storytelling, you show up to see what life-or-death situations Tom Cruise insists on putting himself through – something I think the trailer understands, given that it's basically nonstop action.
At least those close to Tom Cruise can stop worrying about his health every day he's on set now. Tom, you're over 60. You can stop doing your own stunts, I promise.