Yes, but in Japanese, radicals are named differently (even the actual linguistic ones), and the unique names Wanikani gives them kind of reinforces this fact. It’s kind of like if I, as a native English speaker, were to try to learn Spanish. It’s just close enough to English for me to think I can take shortcuts, but I really can’t. I have to approach it on its own terms.
Frankly, I don’t think Wanikani should have named them radicals. Maybe “eggs” or something turtle themed, but it gets confusing when you’re trying to compare them against actual radicals, such as in Chinese or Japanese. They aren’t radicals, not in the sense of either language, and even if you know the shapes, it helps to be able to use the terminology that Wanikani wants to use. I think others have brought up that point, though, so I’ll leave it there.
(I don’t think Wanikani should have named them radicals for the same reason Facebook shouldn’t have called them friends. It creates unrealistic expectations.)