Riding cost reduction should be in during prepatch. Apprentice is now 20 for 4g, Journeyman is now 40 for 50g, Expert is 60 for 250g (and SW/Org rep now affects this, too), and Artisan now has discounts as well.
These aren’t critical changes and they haven’t done any, “authentic” mount releases, so it’s unlikely to change.
It’s about 40%~, give or take a bit per level, and it is in prepatch.