Just a bit of info on WH brakes:  There has been a recall on Workhorse calipers for sticking/seizing.  Buddy with a 2007 went through the pain and suffering of trying to get the recall done this last spring.  No parts in Phoenix, supposedly backordered till who knew when!!  Got back to Oregon, and was able to have the recall done at a small dealership in the boonies immediately!!  Go figure.  Recall covered caliper parts and labor.
As to your question on protecting the new brakes, I would say that rinsing off would be a good option, maybe only one worth doing.  Don't miss the areas that use salt and/or chemicals.