Always bet on JS. It's a super productive language that's just getting better. It has a lower barrier to entry which means it's welcoming to newbies and people from other languages while still having higher level constructs like closures, first class functions, and generators which allow for beautiful abstractions. I think JS will be here for decades to come.
GraphQL is great. I think we'll see it continue to expand across companies and be more common going forward. Microsoft is indeed using it in production.