They are, and we do have those issues; we address them somewhat towards the end of the post, with São Paolo and Tokyo --- but also with São Paolo and São Paolo: a VM that pops up in GRU has to post to Consul in IAD before other GRU nodes "see" it in Consul. We've addressed that problem by "hinting", sending service discovery updates over NATS that usually beat out Consul, and then reconciling the two event sources.
As I understand it, the reasonable-person thing to do here is to have federated Consul clusters in different regions. We run up against the problem that we're not hosting one application globally, but rather a zillion applications; every node needs to know about every instance of every application. So things like losing the global KV store are problematic for us.