It shouldn't. Amazon believes in strict regional isolation, which means that outages only impact 1 region and not multiple. They also stagger their releases across regions to minimize the impact of any breaking changes (however unexptected...)
While I agree it sounds like their networking modules cross-talk too much - you still need to store the networking config in some single global service (like a code version control system). And you do need to share across regions some information on cross-region link utilization.
