Blood and Wine is more like an expansion, like a mini-sequel, than a dlc. Whole new huge area to explore. It's also full of (good) fan service cause it's fully aware that it's the last chapter in Geralts story and wants to celebrate that and leave you with a wink and smile instead of something more serious like the base games ending. I just can't see someone loving the game but not getting that conclusion it's so perfect.
If you played mass effect, it's like the Citadel dlc. A loving farewell.