Azure Cosmos DB now provides the ability to access the change feed (https://docs.microsoft.com/en-us/azure/cosmos-db/change-feed). A common pattern to implement eventing patterns is
1. Store every version/change as a separate item
2. Read the change feed to merge/consolidate changes and trigger appropriate actions downstream.
You can also expire old versions using TTL: https://docs.microsoft.com/en-us/azure/cosmos-db/time-to-live
Work on this feature has started. Will update here when this becomes generally available.
Thank you for your suggestion and votes.
This support is planned for SQL DB Managed Instances:
An error occurred while saving the commentMBacon commented
We echo the same sentiments of many of the other comments - need it in standard Azure SQL Databases, not managed