They could simply be "base weapons", or what we used to call the "pre-relic". That would fit both your explanation and others' where the weapon technically isn't a relic, just the base weapons on which the relics are built, and in 3.1 they become the relic for the first time.
And there's also one possibility: that they are indeed the new relics, but we aren't getting them in 3.0 anyway. They just exist in the benchmark for us to drool over. ;-)