When is Shadow Trap gonna be useful?
Two points:
One, this is not a “new” game in which pathfinding is mystically worse than an “older” game like Day-Z. In fact, GW2 predates Day-Z by a year, and is built on the GW1 engine which is older, and influences some of the systems, likely including the servers.
Two, pathfinding is actually one of the most difficult problems available, and the best known algorithms without pre-processing give `O(|E||log(V)|)` complexity without preprocessing, and are not guaranteed to find the optimal route.
So while it is absolutely possible that pathfinding and, in this case, “legal traversal path” validation, could potentially be improved in GW2, don’t mistake your ability to do it fast and efficiently for the ability of a computer to do so.
This is one of the problems that keeps the best and brightest CS people in the world up nights trying to figure out how to do better.