Yes, at least the Wizard has potentially a large number of subclasses (i.e. arcane traditions) so why making the Sorcerer and the Warlock two of those many? Furthermore, the Sorcerer itself can easily have a decent number of subclasses depending on bloodlines, and I guess there's room for Warlock subclasses too.
The second option, that of replacing the "Wizardry" mechanic with another spellcasting mechanic, is better. Then the arcane traditions modify spellcasting and not everything there applies to wizardry mechanics, so must likely (as suggested by the names of the arcane traditions) there will be separate traditions for wizardry, sorcery and witchcraft. But then take a look at what is left: Scribe Scroll, Brew Potion, bonus Lore and Spell Mastery, which are pretty few to be the unchanging backbone of a class (also the latter is not applicable to Sorcerers if they cast at will as in 3e).
So there is the interesting novelty of lumping all arcane casters into the same class, but then we have to change the "meat" of it when switching to another spellcasting mechanic. At this point, it would be easier to just have 3 different classes, which then can also multiclass...