Public cloud environments are multi-tenant and VMs share the physical server which can result in VMs fighting for resources. Because a bare metal cloud is made up of dedicated servers, this problem is avoided.
People with sleep apnea often wake up suddenly due to shortness of breath. Upon waking, they may also choke, snort, or gasp. You may not even be aware of some of these symptoms while you sleep, but waking up feeling out of breath is a strong indicator that you have sleep apnea.
I don't think you can say they're the same thing. Dyspnea is difficulty breathing, or labored breathing. Shortness of breath is... just feeling of short of breath, like when you just did a two-mile run. You can feel short of breath but not necessarily have difficulty breathing.