Since you claim its exactly the same as previous shutdowns listed; when Google shut down Wave, which paid for Google product were they aiming to increase adoption of?

my memory of wave is that it barely even launched. wasn't it around less than a year? did anyone actually use it?

My group of friends tried to. It could have been quite successful, since it basically offered what Discord is now.

How? I guess you could use it like a chat room just putting new messages at the bottom of the document but seems like a crazy kludge to use Wave as a chat.

I thought that was its intended primary purpose. We could chat and inline media, pictures, etc. It was a big upgrade from IRC. There were issues with sharing files larger than just images and whatnot, but it easily could have been polished a bit into something better. If Discord added the ability to have 'threads', it would basically be what we used Wave for. For a few weeks anyway until Google decided it wasn't catching on enough or whatever justification they gave for giving up on it.

I don't think I ever heard of it being pitched that way just as a collaborative editing room for editing an actual document not just for using the comments etc as a chat.

G-Suite (Docs).