Eddy,
There is no retirement of the Airwave sizing calculator, it is just that the ASE version showed to provide some strange recommendations in some situations.
The link is supposed to point to the Airwave 8 download on the support website (here is a recent one), where under each version an Airwave Sizing Guide is posted. The recommendation is to follow that, instead of the online configurator.
If you get stuck somewhere, feel free to reach out to your local Aruba SE or contact Aruba TAC if you need to have your sizing validated.