Remember, Article V has been invoked just once: Afghanistan after 9/11. We can debate if that was a good or bad action, but strictly speaking, it's only ever been invoked in defense of the USA.
You do read Der Speigel? - ran an article weeks ago saying there would not even be a decision on spending until 2020.
From February: "The United States and our international allies, which for so long has been the centerpiece of what is rightly called "The Free World," are facing the greatest threat to global stability since the end of World War II. Security arrangements, like the North Atlantic Treaty Organization (NATO), which for more than seven decades have kept us safe from yet another global conflict, are quickly coming unraveled."
Granted it has not been stated as clearly as the UK's exit of Europe but the writing is on the wall.
Just because they say they need to be more self-reliant doesn't mean they're pulling out of the alliance. Even Trump, with whom I disagree on pretty much everything, isn't leaving the alliance despite his overheated and irresponsible rhetoric. And "quickly becoming unraveled" is not "we want to leave" it's more "there's a maniac in the white house destabilizing everything that has worked for the past half century".
I would not overstate Trump's impact - you will only give him an even bigger head. In reality he is insignificant to policy as he will be gone soon enough. I would say Putin and Snowden were more of an impact.
In reality by 2024 the Bundeswehr will no longer be committing troops to NATO missions outside Germany (see above). If it makes you feel better to pretend that they are 'still part of NATO' then fine.