Official comment
Anything that was free in version 5 is free in version 6; anything that was a paid upgrade in 5 is now part of the Core or Creative plan in 6. So yes, while you may have paid for the video plugin for 5, you must now pay for one of the plans to have that same functionality in 6.
If you want to use CDJs and a DJM in performance mode, you would need a subscription. The DDJ only unlocks the software when that hardware is connected, the same way Serato DJ Pro works.