There are certainly different possibilities of where the line would be drawn. I am not that familiar with vim internals, but I don't consider file management to be part of vim editing model. And we are only talking about editing model (e.g. b being beginning of a word), not the whole editor (plugin system, ui, lsp and treesitter integration, etc). Though it is true that some parts are more tightly related to "vim". There some cases were Neovim already wants to disconnect itself from vim legacy like allowing to scroll viewport without moving the cursor

By "recreating everything" I was also referring to the ecosystem around the editor