This ruling has such a major impact, I don't think the USSC will publish their ruling until the last day.
And I don't think it's a "Chicken Scotus". The ruling is likely a very lengthy document that will need careful editing prior to its being released. There is a reason that the rulings are released over several days during the two-week period; that reason is that every one of their documents must have appropriate language and go through multiple markups in the majority opinion and the minority dissenting opinions as well. These edits take a lot of time. The Court is merely getting those that are easier to go through this process out of the way first.
What in the world would the Justices have to fear?