This move might take the pressure off of Mishra's Workshop, but it doesn't give much of an explanation as to why they are pumping colored artifacts and not simply enchantments:
This makes perfect sense for color pie reasons.
From the discussion at the end, I don't think enchantments are being de-prioritized in any way, I read the shift as being within the artifact space. For example, if 18% of good cards are artifacts and they're 17% colorless 1% colored in the future it will be 1-17 instead of 17-1. I don't read the article as saying anything about artifacts being boosted ahead of enchantments.
I think there's a bit of a natural flavor differentiation between artifacts and enchantments, which Wizards should try to push further. Namely, artifacts sometimes tap and/or sacrifice to function, while enchantments very rarely do. Enchantments frequently have static abilities, while artifacts have these abilities somewhat less frequently. If I were in charge of design for Magic I would try to have firmer rules about what mechanics go onto what card type, extending the historical mix into something players can recognize intuitively.