Yeah, that's true. (And even likely) That said, there's that moment when Kapura and a few others, including Miserix, got teleported into space. As far as I remember, they're both fine - not sure what the implications of that one are.
EDIT: Willess, were you giving that as a reason for why Matoran do, in fact, need certain stuff to breathe, or were you suggesting that the Ta-Matoran didn't die? Pretty sure that said Matoran would have fallen pretty far if Teridax was still making his way off Aqua Magna in the GSR.