Just to bring another bit of evidence into the discussion and return to a comment about savescumming:
1. artifacts don't change their name, but do change their type when you savescum (so if you are getting something call the Merchantfrumpt the fumbling of Cats you will still get it, but it might be a barrel, or a bed or a table--whatever the workshop in question makes). This means it would make sense for an artifact to expect another artifact by name, but that it makes no sense to expect another by type.
I'd be interested in seeing if the armor-stand artifact that was predicted is savescummed as it is about to complete, and if it will in fact turn out to be an armor-stand after the savescum, and whether the prophesying artifact changes to adjust or continues predicting the wrong thing
2. In older versions, right after the ghost release, ghosts of dwarves who died moody represented them as the creators of artifacts, even when no such artifact existed. This suggested that dwarves who began to make an artifact, were, as far as the game is concerned, fated to complete them, regardless of the actual outcome. This too make me wonder; since it implies some sort of fate system in the raws that works to construct the dwarf identities. Ok, that sounded a little too comp. litty.