iCal has no cancellation event, so a disappearance is a hypothesis, and "possibly cancelled" is how Lemon holds a hypothesis without acting on it. The badge appears on the host dashboard; nothing is sent to the cleaner. Each further fetch that still lacks the booking adds observed absence — capped at 10 minutes per fetch so outages between fetches do not count — until the window is reached: 24 hours when checkout is more than three days away, 2 hours within three days, never within 24 hours of checkout.
The host can shortcut the wait either way: confirm the cancellation (job cancelled, cleaner told) or "Keep it" (a host hold, re-raised for review after 7 days).