After discussing it with several contributors, the decision has been made to officially remove IE11 support in WordPress 5.8.
The removal will be done in two phases:
- WordPress 5.8 (among other changes) will effectively remove IE11 support in the block editor and all generated CSS files used within the admin.
- WordPress 5.9 will focus on individual tickets that might be created to evaluate removing each instance of IE11 specific code.
