I hope it’s actually a mistake and Shield of the Righteous goes back to where it belongs, Protection. Retribution has no use for a shield, you are there to do damage.
It would be nice if our gear was saved to our spec, not in our inventory at all. That way you’d only have to carry around things you might swap like Trinkets for example. I carry my sets for Prot and Holy too and it just uses up too much space.