Guys, it's not unusual for japanese artistes to release something like this during their silver, golden, whatever anniversaries. It in no way signals she's going to retire. It's also a very profitable venture since the japanese buy into all that commemoration idea. I believe it's going to sell well looking at ayu's compilation sales trend except for A-ballads but that's probably because that album had almost no reason to be released. A 10th anni commemoration is a HUGE reason to be releasing a compilation album that encompasses every single from 8.4 to 8.4 so to speak.
Initially, i was frustrated when i saw the news of this release as well. What's the point of A Best 2 then? But i believe this is a very japanese mindset. The purpose is of the utmost importance. A Best 2 was to signal a 3rd chapter of her music career. This release is purely for the 10th anni spirit. Very corny for many cultures i think but there you have it. If you cannot understand this reasoning, then this release will probably annoy you very much, especially if you are a diehard fan who is buying this purely to support ayu. Ayu is very fortunate to have so many wonderful fans on this forum