Now that Thameslink and Southern are effectively the same franchise
Not just yet. Southern is still a separate company in the GoVia family until next summer. Thameslink, Southern and Southeastern may have the same overall company, but the management are different. This explains to some extent why Southeastern continues to poor in comparison to Southern.
Next weekend, all trains will operate on Saturday. On Sunday the overground is running normally with a reduced service to London Bridge on Southern.