I’m having the same issue, no such setting on my Settings tab, logging in and out doesn’t seem to help. Still don’t have permission to create extensions or have the setting 
Edit: It seems you’re correct @Ocgineer that it uses the Partner tax stuff instead, as on my Partner Settings I can see “View Extensions Developer Agreement” with the green tick mark. I would guess the developer website just takes awhile to update, I’ll check back in an hour or two.