DNSSEC remains on our long term roadmap, however it is unlikely to be available in CY 2019. If DNSSEC is a critical and immediate requirement for your business we’d suggest that you consider evaluating 3rd party DNS hosting solutions that provide this feature.
Thank you for your feedback. We are currently in public preview of static website hosting for Azure Storage to enable this scenario. Check out the blog post here for more details: https://azure.microsoft.com/en-us/blog/azure-storage-static-web-hosting-public-preview. The feature set includes support for default documents and custom error documents for HTTP status code 404.
For any further questions, or to discuss your specific scenario, send us an email at firstname.lastname@example.org.Darrell Enns commented
Why does this need to depend on custom SSL domain support? Even without SSL, it would still allow serving unencrypted content, serving https using the azure domain name, or serving HTTPS with custom domain names by chaining it through CDN.