Will the concept of grammar adaptivity end up on the ash heap of history?
In the early nineteenth century, the concepts of mathematical physics had got way ahead of the available techniques. The dominant conceptual entities were vectors (i.e. directed magnitudes) while the dominant technique for physical description was Cartesian coordinates — very clumsy for describing vectors. Once the requisite vectorial tools were made available, did everyone flock to them? No. It took decades. But sooner or later it had to happen; the more physics advanced, the more pressing the need for vectorial techniques, until finally it happened. (The immediate stimulus was probably Maxwell's equations.)
The concept of grammar adaptivity is inherent to the abstraction mechanisms of virtually all programming languages. The more powerful the abstraction, the more prevalent the concept. (See for example [Dahl 72].) Suitable techniques are just beginning to become available. So now it's just a matter of time. Sooner or later, adaptive grammar techniques of some kind will become common practice. (All things being equal, I'd rather it were sooner, so I can see what happens. William Rowan Hamilton, for example, who cleared the way for vectorial techniques, died decades before they caught on.)