I try to give you a short answer here - as short notice from the other threads...
Customers who have registered for Microsoft.SQL will receive these notifications, Even though if the customer did not create the Azure SQL DB they receive it due to the Microsft.SQL is registered for the subscription.
it's a general notification to existing SQL Database users to transition the new APIs by October 2025
easiest way to get around this "issue" will be updating the SDK to a newer version (after mid of 2022)
there will be coming up more details on this retirement in the next few weeks => here: https://learn.microsoft.com/en-us/rest/api/sql/retirement