I set "critical" for this bug, because it affects not only simple mode. It break simple and ha if you choose mongo role for node without controller role. So, roles cinder+mongo, mongo will fail to deploy. So, it's possible to setup mongo only with controller on one node. It's really important to have ability to deploy mongo on any node you want. So, it should be fixed ASAP.
I set "critical" for this bug, because it affects not only simple mode. It break simple and ha if you choose mongo role for node without controller role. So, roles cinder+mongo, mongo will fail to deploy. So, it's possible to setup mongo only with controller on one node. It's really important to have ability to deploy mongo on any node you want. So, it should be fixed ASAP.