The fact that we still get surprised by new elements of the brain suggests that there quite a lot we still don't know about the brain

Indeed, and more big surprises are bound to surface.

and uploading might be harder than previously believed

I'm sure uploading will be hard, but the discovery you mention (which looks like some extra plumbing infrastructure for the wetware at this point) does not seem to fight the idea that the cognitive processes can be abstracted and extracted from the wetware.