They're in continuity technically. They are just noticeably contradicted by other events. Ewing actually makes a reference to LT being reborn in Ultimates, which is clearly a reference to what Starlin wrote. It can be argued that the LT killed by Order/Chaos is the Warlock/LT.
in one of the printed fan letters in a late rissue of the Ultimates, that same question about Walock was asked and the response was that they purposely left it vague but you could interpret that it was Warlock