They were also called "Sons Of Kyuss" at the release of Sons Of Kyuss. So technically not "Kyuss".
I guess it's no biggie though, because SOK, the release, is roughly the same album as Wretch anyway, Wretch just has more on it. Not to mention nothing really changed when they changed their name to Kyuss.
But yeah, to be absolutely technical, the debut album for "Kyuss" is indeed Wretch.