In my request to Microsoft support they said they were sending out these warnings to anyone using Microsoft.SQL in their subscription which is anyone using Azure SQL databases basically. They said that if we are using Azure SQL Database, the APIs will automatically be updated. Also. if we did not write any code or use any third party software that make calls to this REST API for SQL for managing the server, then we do not have anything to upgrade.
Quote from Microsoft support:
The retirement of the 2014 API will not affect any Azure PaaS or SaaS products that are kept up to date, as the API will be updated automatically. For any 3rd party or unmonitored items that may use the old 2014 API, they will need to be updated by this time to avoid incompatible calls being made to the target databases.
Azure SQL Database 2014-04-01 APIs will be retired on 31 October 2025 - Microsoft Q&A