But your example cites a "natural born American", not an immigrant?
When you immigrate to any country you know very little about how the country really is and how well it'll treat you. It's up to the country to gain a citizen, otherwise the ties are just monetary while the job lasts.
An immigrant who hasn't at least applied for citizenship definitely doesn't owe loyalty to their country of residence.
If your hiring program is built around increasing diversity, and you have an enemy state who would count as diverse by default then you have quite literally opened the door for exploitation.
All the handwringing in the sibling comments are not even trying to contend with this.
Also, it seems to be second generation migrants with greater affinity for extremism and patriotism for their parents country - despite never living there (this is the case in Sweden at least), and those are usually full citizens: this is very difficult to contend with for security services who use citizenship as a proxy for weeding out potential disloyalty).
You'd be surprised. If I were to emigrate because of economic reasons (which is by far the most popular reason to emigrate) my loyalty would stay with my paychecks. I don’t see how it could be otherwise. What binds me to my new country? My history, my character, my race, my religion…? Guess not.
Not necessarily true. Source: I have friends and family who came to the US from Russia and are still loyal to Russia. When the topic comes up, they tell me they would fight for Russia in a hypothetical US/Russia war.
It's entirely possible to love your country and still seek out a better life elsewhere for practical reasons.
Edit: To clarify, this isn't universal. Some folks who came over absolutely hate the country of their birth, some still love it, while others are ambivalent. But you can't make a blanket statement like "people loyal to their country tend to stay there" when there are stark financial and quality of life advantages to moving from one place to another.
A company hires immigrants.
It's possible the company has hired immigrants loyal to their country.
Logically, it works like that.