It's certainly an interesting idea, and could make for a fun bit of headcanon or some great fanfic/comic/game fodder; Bo-Matoran seems a touch more likely to me since he still seems pretty at-home in Le-Wahi. Of course, he could also just be a bit of an oddball, and it's not like there aren't other atypical Matoran of a given element.
... Might steal this idea for myself though, hehe.