My numbering has misled you, it’s not intended as a season finale. Those season numbers really just represent production blocks, as I was working to pace the whole thing. They’re not really intended to be public facing in this context, except to help identify the rough ordering. Once I was done with the show I was going to think about whether it should be presented as seasons, and maybe change the numbering for public consumption. Bear in mind the original show also had no sense of season finales either, the seasons never really built to a conclusion like a typical TV show should.
That said, we’ll see Maul in about six more episodes time, and see that scene from the opening episode a few more episodes later, if that helps judge whether or not the stinger belongs.