“Is this the beginning of a Celtic renewal?”
There have been signs of a Celtic revival in Brittany as well: http://eucenterillinois-language.blogspot.com/2014/12/defying-odds-resurgence-of-breton.html
Even Cornish is making a comeback: http://www.bbc.com/culture/story/20180412-the-rebirth-of-britains-lost-languages
It would be nice to save those endangered languages