I expect that there are a lot of discussions taking place between shipping company lawyers and insurance carrier lawyers before the captains get the green light to cross the line.
Red dots and arrows are oil tankers. Pink dots are navigation and weather buoy's, and shallow sunken vessels that a ship might hit.
One can click on any of the dots or arrows and in most cases see a photo of the ship and details which include their destination even if they are at anchor waiting for an opening to go in and dock. The flag they are sailing under and the company that owns them are also details that pop up when clicked.
What I see happening is a bunch of ships are waiting because of the end of the grain deal. Most of them look like they are ships that would haul bulk cargo like grain.
It is as you have said, they wait while the shipping companies are figuring what to do next. While I was writing this post 4 ships got underway and they all appear to be heading away.