User blog comment:MisterWoodhouse/Updates to Discussions and the plan for Forums/@comment-5645428-20200811002825/@comment-24006128-20200813202216

Boards become Categories.

The migration overrides the limit, but if you delete categories, you cannot continue to go over the limit with new ones.

If a Board matches an existing Category name, a duplicate will be created and the content will need to be manually transferred to the desired final category.