On 4.16, when scaling up rhel worker nodes on azure platform, we found that rhel vm to be provisioned requires below additional conditions to ensure that scaleup operation is successful.
1. size should be Standard_D8s_v3 (8cpu, 32G memory)
2. enable Accelerated Networking

suggest adding notes in doc[1] and [2].
[1] https://docs.openshift.com/container-platform/4.15/machine_management/adding-rhel-compute.html#rhel-compute-requirements_adding-rhel-compute
[2] https://docs.openshift.com/container-platform/4.15/machine_management/more-rhel-compute.html#rhel-compute-requirements_more-rhel-compute     

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