The change in METAL-1509 means that we are now looking at the architecture field in the PreprovisioningImage.

For ARM clusters upgraded from previous versions, this should be OK as we will get the correct architecture from the inspection data.

However, to do the initial installation, we must have a PreprovisioningImage available in to do inspection. Since BMO always sets the default arch to x86_64 when there is no inspection data, we are probably unable to install on ARM after these changes.