Cannot set ports for services not on node in 7.1

TestRemoveServerClassWithNodeService and TestExposedFeatureIP are failing on 7.1, both with the same error message:

unexpected status code: request failed PUT http://test-couchbase-cf8n9-0001.test-couchbase-cf8n9.test-cp89j.svc:8091/node/controller/setupAlternateAddresses/external 400 Bad Request: Cannot set external ports ["kvSSL","kv","capiSSL","capi"] as services are unavailable on the node. 

I think this indicates an issue with GetAlternateAddressExternalPorts() and how it interacts with the new, stricter, rules for setting external ports in 7.1 as changed in MB-49376