What happens if your vSphere server will lose all the management network connectivity ? Well, once again, the right answer, it depends !
By default, vSphere 5 and 6 are configured to do nothing. Meaning that your virtual machines will remain powered on and located on the host. So maybe this is not exactly want you want for your cluster and depending on your configuration, you could have a production impact.
To avoid you some bad surprise, I’ve listed some settings recommendation based on the most common Simplivity deployment. And once done, please test it !
If you want more information about the host isolation settings, there is a nice post here.