Here is a link to the ground footage where the no_u_turn restriction is visible. https://www.mapillary.com/app/?lat=11.58336&lng=104.900178&z=17&focus=photo&dateFrom=2017-01-01&pKey=656602739802377

Even if no u turns are implied, it helps to add the restrictions in order to prevent the u turn. If some navigation software doesn’t process that information then it shouldn’t disrupt their routing. Other softwares do process no u turns restrictions, so it would be important to add them for those types of routing software.