The module azure_rm_virtualmachine has fields for plan information. Module azure_rm_virtualmachinescaleset needs to have them and forward them when creating a VM with an image that requires plan info to be specified. The CIS hardened images from the Azure Marketplace is a prime example.

required: true
    state:
        description:
            - Assert the state of the virtual machine scale set.
            - State C(present) will check that the machine exists with the requested configuration. If the configuration
              of the existing machine does not match, the machine will be updated.
            - State C(absent) will remove the virtual machine scale set.
        default: present
        choices:
            - absent
            - present
    location:
        description:
            - Valid Azure location. Defaults to location of the resource group.
    short_hostname:
        description:
            - Short host name.
    vm_size:
        description:
            - A valid Azure VM size value. For example, C(Standard_D4).
            - The list of choices varies depending on the subscription and location. Check your subscription for available choices.
    capacity:
        description:
            - Capacity of VMSS.
        default: 1
    tier:
        description:
            - SKU Tier.
        choices:
            - Basic