My understanding is that the change from gnu to gnu1 is the result of changes that were needed to the deblobbing. Specifically to allow the loading of the firmware used by ath9k-htc, now that it's free [0]... i.e. 3.3.8-gnu and 3.3.8-gnu1 aren't the same source code.
[0] https://www.fsf.org/news/ryf-certification-thinkpenguin-usb-with-atheros-chip
