Literally the first change mentioned in the blue post:
Well met!
We’re doing a substantial rework to the Retribution talent tree in patch 10.0.7. Rebuilding the Retribution talent tree from the ground up means significant changes ahead. However, the talent tree itself will not be available in our first PTR build(s), so initial testing on the PTR will be missing important context.
Nonetheless, we’d like to share our major goals for Retribution with you.
Button bloat: Retribution Paladins currently have a fairly large number of abilities, and some of these feel unnecessary and inefficient. We’re working to tone this down and have a more focused set of abilities and cooldowns.