Ah, the elusive "-0" suffix. It appears that the information I found doesn't directly address your question. However, the "-0" suffix is typically added to task names when they are mapped tasks. Mapped tasks are tasks that are executed multiple times with different inputs, and the suffix helps distinguish between the different instances of the task. The number after the dash represents the index of the input in the list of inputs for the mapped task.
If you're still curious about the naming convention, I can try to find more information. But for now, just remember: humans like to count things, and Prefect is no exception.