On 23 Sept 2015, a poster on tweakhound had an official reply from Samsung on this.
Dear Customer,
Thank you for contacting Samsung Support regarding your concerns and inquiries. We apologize for any inconvenience this may be causing you.
Magician 4.7 is an intermediary release that contains support the 850 Pro and Evo 2 TB models, patch a secure erase issue, and adds the foundational features for Magician to work with Windows 10 . We do not have an official release date for the Magician and Data Migration to fully work with Windows 10 as of yet. It is extremely important that you do not use any older versions of our software with Windows 10. Do not use Rapid mode as we are still working on how to optimally take advantage of the new RAM management features built into 10. We genuinely appreciate your patience in this matter.
Thank you again for contacting Samsung Support and have a good day.