I've been visiting the Vasa every few years for 3 decades and there has never been a time when museum goers were allowed onto or into the ship. I haven't been to Stockholm since the start of the Covid pandemic but I very much doubt that has changed.
They do have some rooms on the side with mock-ups of some of the ship's quarters - maybe that is what you are remembering?
They do have some rooms on the side with mock-ups of some of the ship's quarters - maybe that is what you are remembering?