Drupal VM 5.1.0 was just released (release name Recognizer), and the main feature is PHP 7.4 support; you can now begin running and testing your Drupal sites under PHP 7.4 to check for any incompatibilities.

PHP 7.4 includes some new features like typed properties, arrow functions, and opcache preloading which could help with certain types of code or site deployments (I'm interested to see if opcache preloading could help the startup time of Drupal inside container environments like Kubernetes!).