Please see the SQL Server Management Studio release notes for a comprehensive list of bug fixes. 

SQL Server 2019 is designed to solve challenges of the modern data professional including:

• Store enterprise data in a data lake and offer SQL and Spark query capability overall data
• Reduce the need for Extract, Transform, and Load (ETL) applications by eliminating data movement
• Integrate and secure machine learning applications with scalable performance
• Reduce the need for application and query changes to gain a boost in performance
• Increase confidential computing of data through hardware enclaves
• Increase application and database uptime and availability through features like ADR (Advanced Database Recovery)
• Extend the power of the T-SQL language in a secure and robust fashion
• Run applications and deploy databases across multiple operating systems and platforms with compatibility
• Reduce the risk of upgrades while using new SQL capabilities when you are ready though inbuilt database compatibility levels 

Introducing the SQL Server 2019 video learning series 

A beginner’s guide to database deadlock 

A Guide to SQL Naming Conventions 

Mssql extension for Visual Studio Code now has Object Explorer and IntelliCode 

SQL Server 2019 Standard Edition Feature Limitations Are Out 

TL; DR: If you are not absolutely certain that you should be using the UTF-8 collations, then do not use them! 

Impact of UTF-8 support in SQL Server 2019