WA 519 has never been well signed. Its signage has disappeared over the years due to construction in that area. The last sign that I knew of was on the viaduct on the exit for South Atlantic Street. It may well no longer be signed.
On paper, it is still officially routed along South Atlantic and Brougham Way as a pair to Alaskan Way and up Alaskan Way to Yesler. The routing along 1st Avenue and Railroad Way was published as a construction detour, not as a rerouting. Eventually, Atlantic and South Brougham will be connected to the new Alaskan Way and the on paper routing will be usable again. Whether signage for WA 519 returns is an open question.
Hurricane Ridge Road does begin at Mount Angeles Road (way point MTAngRd). Race Street ends and Mount Angeles Road starts at Park Avenue (way point ParkAve). It looks like whoever created the mapping included the section of Mount Angeles Road to include a waypoint for the Visitor Center.