WordPress 5.8 will start integrating new features that have to do with a migration towards full site editing. As far as widgets are concerned, the old drag and drop interface will be replaced with a block based widget areas.
It is likely that widgets are to replaced entirely by Full Site Editing template areas. So instead of having of having Footer Widget 1, Footer Widget 2, and Footer Widget 3 – you will now have a Footer Template with a columns blocks.
Make sure to keep an eye on the widgets when updating to 5.8!