This happened a couple days ago, noticed when spinning up a new RDS instance.
I'm super excited about it. It's great to have more modern managed services on AWS especially since this brings Postgres out of the Stone Age. Lots of good JSON support added in 9.5 and 9.6.
9.5 was actually added to RDS back in April [0]. There was some serious bugs found that made them wait for 9.5.2 before adding it [1]. As a customer of RDS, I'm really happy that they're taking their time to thoroughly test the releases.
I'm super excited about it. It's great to have more modern managed services on AWS especially since this brings Postgres out of the Stone Age. Lots of good JSON support added in 9.5 and 9.6.
Previously only 9.4 was available.