I agree with the other commenters that there are plenty of people working on Scala (and arguably odersky is a much better researcher than he is a maintainer) that I wouldn't worry about people maintaining/upgrading Scala.
I do think 2.12 (and 2.11 before it) either had unrealistically optimistic deadlines or suffer from poor project management. 2.12 has slipped by well over a year at this point, which is sad for frameworks like Spark which are going to stick to 2.11 for their next MV cycle.
I do think 2.12 (and 2.11 before it) either had unrealistically optimistic deadlines or suffer from poor project management. 2.12 has slipped by well over a year at this point, which is sad for frameworks like Spark which are going to stick to 2.11 for their next MV cycle.