Yup, that's correct, though the old library in my repo still works and is used by some folks, maintenance of SoCo is handled by a group of very talented and friendly developers under https://github.com/SoCo/SoCo
It looks like the author used SoCo for the Raspberry Pi project mentioned at the bottom of the article.
Re:Hacking Sonos
by cushychicken on Wednesday April 23, 2014 @03:09AM
(#7632591)
Hey Rahim - you did great work on that project. I've used it a few times with an RPi to control my household. Works like a charm!
Also, the author used his own Sonos library written in ObjectiveC rather than Python: https://github.com/nathanborror/SonosKit