Well, it was a ‘recruitment’ endeavor for all types. I imagine that means R&D people too. And you are aware they’re beyond the pigs now, right? They implanted a monkey and taught it to play video games.
Unfortunately (or fortunately depending on your view of the living), R&D involving animals, and even more so people, is subject to a lot of moral and ethical questions nowadays which often slows progress to a crawl.
I would say their current approach to nail down the safety of the technology, the ability to add or remove it with no ill effects, to make it practically unnoticeable, to have it implanted and removed by the precision of a programmed robot rather than human hands in a matter of minutes etc... is the best choice.
I would also say that when the time comes, human volunteers will line up for the chance to be a guinea pig, and that as Elon has demonstrated before, smart people will want to work there.
I think, as is your tendency, your concerns are misplaced and focused on the wrong aspect.