All comments of User WoodOfTheRisgingSun
NO. Marina Shiina 椎名まりな did not delist her videos. Search by her Japanese name on DMM you can find all her videos back to her debut in 2013. So if some sites don't list her it's each site's issue. On DMM, and Amazon, her videos are still on the shelves. However, she retired sometime between 2015 and 2016. So the 5-years rule will be available to her pretty soon. Doesn't mean she will delist them, but you will never know. And there will be no warning at all, the application process when it happens will be sudden and irrevocable. If you are a fan, pick up any physical copy or DRM-free digital copy over the next few months. Maybe next few weeks. If her retirement date was calculated to be late 2015, it could be any day now.