There is no definition for a temple artifact, which Priestly artifact includes in its own definition.
There is a current definition there as welI, so that is moot to the discussion of Priestly (it only has to reference the list, not include the definition of Temple/Tabernacle).
I also know Temple/Tabernacle is being beefed-up for the next release, so something about that should come out soon or when the REG is published.