The threats about suing was some drama that happened back in the end of December last year.
The link you posted is to a fork by a guy who made a video about it back then.
https://www.youtube.com/watch?v=3wz7YF2as-c
It's 15 minutes long. Basically, the original theme author was threatening to sue people, even though he had released his project under the Apache License 2.0.
https://news.ycombinator.com/item?id=43178831