The people at Kinsta published a nice overview of all changes coming to PHP 7.3 which will be released in December.

In this post, we’ll provide an overview of the features and changes that we personally consider most relevant. But you can always check the full list of features, changes and bug fixes in PHP 7.3 upgrade notes and PHP 7.3 Requests For Comments.

https://kinsta.com/blog/php-7-3/