Yes, you are wrong. The main programmer responsible for the Waves back-end has made a lot of changes since the launch of the testnet: middle of August:
https://github.com/wavesplatform/Waves/commits/masterThey want to be absolutely sure that the testnet is running stable for and extended period of time(few weeks) with alternating middle and heavy load. That's why there was relative calm in the last 1.5 week.
You are right on the devnet. They have an own developer network where most of the work is being done. If a module is ready for testing they upload it to github.
Since the launch of testnet there is only a bunch of version number changes and one test config edit. Correct me if I'm wrong.
Let me guess, all the important changes must be on the private branch not visible to outsiders?
github is easy to find, contribution are real.