Uh, I'd say it almost certainly does significantly change their chance of divorce. If you go from having a steady, high income to variable work with high uncertainty around your next paycheck of course it will put more stress on the marriage and substantially increase the risk of divorce.
To be sure, it could very well be that they had some "come to Jesus" moment and decided that's what they really wanted to do in life, and it increased their general happiness and willingness to put effort into all their other relationships. But that, I would think, is the exception, not the rule.
Edit: Though it might be correct to say that the job-change is not a causal driver of the divorce, but merely affected by the real cause.
And even this would make them a non-central example of physicians (and bartenders). Most doctors are heavily committed after 10+ years of education; many bartenders are not "living their dream" and expect to move on. Someone who willingly makes that swap because they've found their true calling is incomparable to the average for both careers.
This is an interesting claim, because I've read various things claiming the opposite (that medicine is a career with a high rate of people leaving it, because the eventual pay and working conditions are simply horrid).
What happens if someone inherits 5+ million and wants a less stressful occupation that's not simply traveling around the world? Well they probably do something well outside of the norm.
Of course, this ignores the fact that sometimes divorce might be a "good" thing where a cash infusion allows someone to leave a bad spouse they were financially dependent on (or, more cynically, "upgrade" their spouse).
If instead, this was a joint decision, I agree with the authors assertions--making a change in career would not impact divorce risk.
If it helps imagine going from "misc. personal appearance workers" to "massage therapists."
Where's your data to break the Null Hypothesis?
Though, if the author of the article wanted to back up their claim, they would attempt to show to what degree drastic changes in career/income had ok divorce rate.
It's obvious that OP (morgante) is posting as conjecture rather than canon.