Two walks are wearing the same hat. The heading Great Sydney Coastal Walk — credited here to the Wall Street Journal — is the long urban-fringe idea, tens of kilometres of headlands, suburbs and ferry gaps, sometimes quoted around 80 km. The body then sends you from Bundeena to Otford. That stretch is NPWS The Coast Track in Royal National Park: about 26–27 km, usually two days, sandstone cliff, heath, Era shacks and Palm Jungle. It is not an 80-kilometre day, and it is not Bondi to Manly.
Royal was reserved in 1879 as The National Park — Dharawal country, the second national park in the world if you count Yellowstone first. Walkers have been cutting it into sections for as long as there have been trains at Otford and a ferry at Bundeena. Keep the WSJ name if you like the sound of it. Just don’t hang 80 kilometres on the Coast Track. If you meant the long city walk, say so and pick a map. If you meant Bundeena to Otford, that’s 27 km of national park, and that’s already enough.