Not entirely dead yet
The proposal’s three goals are to migrate Wave’s codebase from Google to the ASF’s infrastructure, to get Wave back to a state where development can be continued and to add new committers to the project. While the proposal notes that there is a risk to adopting Wave as an ASF project (it notes that Wave didn’t gain sufficient traction at Google), it also claims that its use by the U.S. Navy and other adopters makes it a worth project.
Apache Wave is still a proposal though; the ASF still has to accept the project. With a well-developed codebase and some big committers, we expect that this project will see the light of day. If it does, Wave will have been given a second life.