This has always been present with OFP, with or without Resistance. As explained many times in the past, the preview mode in the editor by default begins in the Veteran difficulty mode, which by default does not show waypoints for infantry.
You don't actually have to play a single player mission to get the editor into the cadet mode. You just have to start *any* mission--SP or MP--as far as the briefing screen, then abort the mission. Thereafter, the editor will be in cadet mode and you'll be able to see the waypoints.