I think the point is that they know no-one will check. There was a tour of a hospital when the IDF never said there were routes to the bunker. It was just a bit of a show. They said it was next door and no-one bothered to knock on next door, or if they did they were turned away.
The easiest thing in the world is for the Lebanese army to go in and say “look theres nothing there, don’t bomb the hospital” but of course no-ones going to do that because a paramilitary group occupies the site.
They can’t move whatever’s there because Israel is watching and so is the public. They can’t have people going in and out because it helps the IDF identify hezbollah members. It’s quite clever really. They just have to periodically put a statement out saying “theres a shit ton of money over there” and hezbollah can’t use it (i.e. to pay it’s staff) It also means they don’t have to actually bomb the hospital.