This could be an elegant solution. I've also been seeing the discussions on Magic Spheres which could also work, if they spend enough time balancing out the schools (or Spheres)
Unfortunately, the DnD Schools of Magic is one of our "sacred cows". It's been in the game so long that grognards like me have become attached to them and feel very uncomfortable about losing them. (similar to the six ability scores, but i'm getting over my attachment slowly... )
The problem is that the Schools are likely not going anywhere. Past editions let you specialize in one school, but that lost you access to another school (usually illusion or divination, because the schools are not balanced)
The truth is that the schools are mostly arbitrary as a gameplay mechanic. They could remove them from the game and just call them spells and the game would play almost exactly the same. But i would miss it...
The 8 Schools also add to the academic feel of the wizard. Its part of the wizard's identity as a "magic scientist/scholar". And i would hate to lose that flavour.
The wizard is the only one who cares about the different schools.
Technically, every sorcerer and cleric's spells also fall into schools, but they don't give a damn. And they ignore the wizard trying to explain to them how the revivify spell they just cast is technically of the necromancy school.
I figure that if we are that if we going to keep the schools (and i am open to dumping them, in spite of my biases. maybe...), let the school specialization have a smaller effect, or a series of ribbon abilities, to add to the flavour, while the wizard subclass becomes the real meat of a character's playstyle.