There will always be more American recruits than the guest workers, anyway, and the military has been known for decades to be a way into the middle and upper class, for those with limited skills, who aspire to it.
You’re assuming they mean a real skill. I think anybody who speaks Arabic or Swahili (simply because that’s his native language) is going to be counted as having a valuable skill. Only the naive would think this is directed at Indians and Hispanics; it’s meant to bring in more Middle Easterners and Africans and put them right in the midst of our military.
Recruitment targets have been met and we’re not in need right with a particular unspoken objective in mind.
IMHO, it’s to develop a basically foreign military that is loyal not to the US, but to one person only. Yes, that would be The One.