First, a couple of clarifications: @wersy - I never said that surface normal direction was "random", I said "arbitrary". There are a definite set of rules which are followed. Curve direction is one of those, but there are more. I just cannot, without hours of investigation, tell you what, exactly, those rules are. But, it is definitely intended to be deterministic. Splines, especially, are fiddly when looking at surface normal.
@iulianOnofrei. if you have a case where the exact same set of steps, on the same geometry, produces different results, I would very much be interested in seeing that case. That would be a bug.
Second, in your example, I assume that the "bad" surfaces, such as this one:

were created as two separate surfaces, not one. If this is a single surface, then I agree, that is a bug, and please share a design or a repeatable set of steps to reproduce it. If not, and you then stitch these together, I suspect you will get a self-consistent answer.
Regarding: "It has enough context to easily be created like this:", if we are talking about two separate surfaces, then, yes, technically, there is enough information to make some assumptions. But, that would requires a pretty complex set of logic. On the second extrude, Fusion would have to:
- go back to the sketch owning the curve or line selected
- find that there are connected curves to the selected curves, which are not selected
- and that another surface has been created from one or more of those lines
- if so, collect info about that surface's normal, and create the new surface in a way that would be consistent, were the surfaces to be stitched together later
Given that you can flip the surface normal, and that stitch will make them consistent, I feel confident in saying that Fusion will never go to those lengths. Also, there will be cases where there is no right answer, like in the video below. That third surface cannot be created "correctly", because either orientation would be inconsistent with one or the other of the adjacent surfaces.
Jeff Strater
Engineering Director