After doing some digging it does not appear your solution would work as configured. As you have already found setting a CNAME is a requirement to map a custom domain to Azure blob storage. I am not familiar with Akamai CDN, but it seems like a user was able to do something similar with CloudFlare. Perhaps reaching out to Akamai to see if that is an option? Otherwise you would need to accomplish this by using Azure CDN.
Hope this helps. Let me know if you have further questions or issues and I will do my best to help.
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