The article throws up a link to a review of two studies  and spends the rest of its time freely asserting that "engineers" are arrogant people who lack "openness, kindness, and curiosity". Here's the closest it gets to some evidence:
>I know several people at Google just like that.
But OK, maybe the study actually offers good evidence that the author article missed?
From the HBR summary, the first study had ~100 engineering students fill out a questionnaire, do either a 15-minute guided meditation or stress relief video, and then either "list as many alternative uses for a brick as possible" or "list all the factors they would consider in designing a retaining wall for a river flood scenario". They found that self-reported mindfulness in the questionnaire was positively correlated with "the number and the originality of ideas that participants wrote down in the idea generation task and with the number of factors considered in the engineering design task".
In the second study, they looked at survey data from ~1400 and found that self-reported mindfulness is positively correlated with self-reported "confidence in one's ability to be innovative".
But neither of these things demonstrate that engineers are narrow-minded. They don't even demonstrate that mindfulness meaningfully affects creativity. They just suggest that self-reported mindfulness is positively correlated with producing ideas for a small toy task and confidence that one is creative.
It's a big jump from those conclusions to "mindfulness should help engineers be more creative". And then it's an enormous jump from that to "engineers are narrow-minded".