"HERB: ...the morning he was scheduled to begin work, November 16, 1966, John Drew Barrymore disappeared, ignoring his role, his moral obligation, and his contract."
It is in accord. You can't disappear unless you have first appeared.
That's too narrow an interpretation. It's not like the studio defined the entire universe of discourse. He was out there in the world, and they'd contacted him before to arrange his guest spot. If he hadn't reported for work that morning, and they tried to locate him and there was no sign of him anywhere they looked -- if nobody, not even his agent, was able to locate him -- then it would be natural to say he had disappeared.
Besides, the first part of that sentence is the telling part. "The morning he was scheduled to begin work." Saying he disappeared in the morning means that he didn't disappear at lunch. And saying "he was scheduled to begin work" indicates that he never actually began work -- he was expected to, but didn't. The sentence is quite clearly stating that he never showed up at all.