Official release announcement - https://code.visualstudio.com/updates/v1_84#_floating-editor...
Floating windows feature is available in the VS Code Insiders channel - https://code.visualstudio.com/insiders/
The announced feature doesn't actually address the original issue raised and is much less useful than the features the OP ask for.
Personally it is rare that I need to display two documents in two seperate windows, but to have some of the tools in seperate windows. That I use all in the time in visual studio proper.
There was some notions about called SmartUI, back in 2015, that we're looking at decoupling this. But never materialized. https://tarruda.github.io/articles/neovim-smart-ui-protocol/
Maybe I want a main editor view in one virtual desktop, but a different editor on the same session on the side of a screen showing off a bunch of documentation, to compare against.
Or I'd like to be away from home & open a web editor, without changing the editor at home. Or maybe I want to let a friend attach their editor & have a shared session we can pair across.
I think it's a mistake to bucket neovim as a terminal program. That is one modality you can use to access a headless program. But it's far from the only one. And the whole point of having a client server architecture, to me, screams not only about the decoupling, but also implies a >1 client capability. Neovim allows this, it's just not very good, since everyone's client has to share a row x column configuration.
Currently it's painful to manage, even with Origami