Decoupling abilities from leaders makes no sense. It destroys their meaning, their uniqueness, their "brand". I can draw a picture on a piece of paper, stick it on my screen and call it my leader. What's the next step, decoupling abilities from cards, because some cards don't see much play and CDPR wants to introduce more cards but not new card abilities? Does that sound silly? Probably because it is, just as with leaders.
As CDPR themselves mentioned, people sometimes forget that they can use their leader, simply because these 3D models don't look and feel part of the card game. If we're going this way, better just remove all 3D models. Gwent is a card game so let's make the 3D leaders into cards again, with cool card art and cool abilities. There can be different versions of leader cards with different abilities, just like in Witcher 3. I can't believe that so many good concepts from beta and even Witcher 3 are simply ignored and not developed further.