Drupal and eZpublish did adopt Symfony, and TYPO3 built their own modern framework (Flow3). Out of these, Drupal and TYPO3 Neos also went with my Create.js libr

Drupal and eZpublish did adopt Symfony, and TYPO3 built their own modern framework (Flow3). Out of these, Drupal and TYPO3 Neos also went with my Create.js library for inline editing. So yeah, there is some precedent at popular CMSs using a modern framework on server, client, or both. We'll see when and if WordPress follows the example...