Version 9.1 of Angular is released by the Angular team. It’s a minor release of the framework and the command-line interface. You  don’t need to change anything in your project, you simply need to drop it as a replacement for Angular 9.0

It comes with new features and bug fixes.

• Support for TypeScript 3.8
• Build Speed Improvements
• New CLI Component Generator Option displayBlock
• End-to-End tests now support grep and invertGrep
• Improved HTML & Expression Syntax Highlighting
• Directionality Query API
• TSLint 6.1 by default

It’s worth to mention that this is the latest minor version of Angular 9 before moving to Angular 10.