These usually get pushed to a full release fairly quickly, but since it’s close to the weekend it might be Monday. At that point, the Beta version of the patch should download. You can choose to download it by right-clicking on Stellaris in your Steam library, navigating to Properties, then the Betas tab, and finally choosing 1.5.1 from the drop-down menu in there. It won’t automatically download, as it’s on an opt-in Beta branch through Steam. One day after the release of the free Banks patch and Utopia DLC, Paradox have put out a Beta patch (1.5.1) dealing with some of the more immediate bugs.
