No, A* heuristics (including extreme ones like jump point search) do not prejudice optimality of the found shortest path, the same that would be found by Dijkst

No, A* heuristics (including extreme ones like jump point search) do not prejudice optimality of the found shortest path, the same that would be found by Dijkstra's algorithm without heuristics. They are only "heuristic" with respect to the subordinate purpose of finding the optimal path cheaply (ignoring as many graph nodes as possible), while the RRT heuristic produces a suboptimal result (not the absolute shortest path, but the shortest path that goes through arbitrarily chosen nodes)