Sure, a GA product like App Engine often has features that are in Alpha/Beta/Experimental states. That different than the major product being in a pre-release state.
Why? The point is, Google has a habit of releasing tons of shiny new Cloud Platform services (whether they're considered "separate products", part of an existing product, or whatever), but keeps them in alpha/beta for a long time. Go support has been there for years, and it's still "experimental". Some of the new products released last year at I/O 2014 are still in alpha, and we're already approaching I/O 2015. Pedantry aside, this deserves discussion.
And...so what? Why does it deserve discussion. Sure, Google openly has always favored a practice of releasing products/features very early to to validate them and evolve them through real-world use with willing early adopters that accept the risks associated with potentially unstable feature sets of not-yet-stable products.
