I realized that while I was writing the previous post, I came up with another simple way to tell if your team is self organizing or not,
In my courses, people always ask me, how to tell if I'm in chaos, learning or self organizing. My answers are usually based on reduction. as is this one.
If your team needs to go ask an architect outside the team questions to finish its job, it's not truly self organizing. A self organizing team should know how to solve its own architecture problems. (That's why feature teams can potentially be self organizing, because they don't need to get out of the team to do their job).
If your team conssists of an architect, it's a different story. it *could* be self organizing, but I would push that architect to use their leadership position in this area so that everyone became the architect (of course, only in learning mode. in chaos you don't have time to do that.)