Actually, that's exactly what it meansand, until the show retcons that for good, that's exactly what it will continue to mean.
Just because the gene runs in the family ...
This isn't True Blood/Buffy: a bite doesn't make a werewolf, the gene does, therefore, as it was established by The Vampire Diaries, Klaus was born a werewolf whether or not "the curse" was activated, just like on Mayor Lockwood's case. Otherwise the Gilbert device would've never affected him and Tyler before the curse was activated.
Lets face this, the writers blew it: they've dug their own plot hole to retcon for this contradicts their own canon.