Jonathan Desrosiers, writing on WordPress.org’s weblog:
When WordPress 5.8 is released in July of this year, Internet Explorer 11 will no longer be supported.
If you are currently using IE11, it is strongly recommended that you switch to a more modern browser, such as Google Chrome, Mozilla Firefox, Safari, or Microsoft Edge. IE11 users have been shown a warning that IE11 is considered outdated in the WordPress dashboard for the last 17+ months.
If you are already using one of the more modern browsers above, you will only be positively impacted by this change, as there are performance benefits to dropping IE11 support.
To be clear, this will really only effect the WordPress dashboard, themes and site front-ends won’t be impacted at all. But it’s a step in the right direction.