So if I remember CS2 was DRM protected, but Adobe was having a bunch of issues with their server, and decided to shut it down.
They released a master key so that customers could still use CS2 even though the DRM server doesn't exist anymore.
In their statement I think they implied that it's only for existing customers, but obviously they're giving up on enforcing CS2 licenses.
So I suppose they could release a freeware version, but then they'd have to release an update to all existing owners and keep some server space for the download, and I guess Adobe thought that that's more work, IDK really.