As of today, the conceptual migration guide for API v7 is available. This guide is intended to be an indication of the changes that will be available in v7. It is not comprehensive and is subject to change with the release. Version specific functional documentation and Redoc links pointing to the APIs and its endpoints will be available after the v7 (GA) release. This release is set for April 1st, 2022.
Please check the migration guide here: https://api.bol.com/retailer/public/Retailer-API/v7/migrationguide/v4-v7/migrationguide.html