Lots of these non aquatic plants grow quite well submerged and in boggy and waterlogged soil, once they stop growing and dying off that's when decaying starts and when any possible Ammonia issues may present themselves, and from seeing healthy fish and plants in a tank that's had one of these plants in it for a relatively long time without issue is the main reason I posted my comments, perhaps certain species of fish might have less tolerance to them should they get eaten, but the biggest concern folks have with these plants is the ammonia caused by leaving dead and decaying plants in the tank, at this point I think it is a most obvious time to remove it, who wants anything that looks a mess left in their tank any longer than necessary?