I don't really understand the question. Are you asking if Fractal Audio's business strategy is to sell more with each new product?
As someone who owned an Axe-Fx II, I'd say there are most definitely advantages to updated hardware when it results in new and improved features that weren't possible with previous versions.
May question is how do you know that? You can't know what was possible with previous versions. If fractal say that you still don't know if that's true or not or if it is fractals business strategy to fool ppl to upgrade and purchase the lastest version.