Lost Island is in a separate category to the other HM flashpoints (shares the same daily BH commms though). So if your not geared enough for it then dont select it on the main panel of the group finder, you will still get the comms.
They weren't talking about HM, they were talking about normal. If you look at the Group Finder, you'll see Lost Island is in the normal mode Flashpoint list. So is Red Reaper. They were saying that Red Reaper is probably more appropriate for a fresh level 50 than Lost Island, so maybe Lost Island shouldn't be in that same set of normal FPs required for the random.