If it's called VimConf, I could understand including content from anything vim related, even vi or neovim stuff (or from the other forks/variations/bases).
But if it's called NeovimConf, I wouldn't expect that to include the entire Vi ecosystem.
That will be changing soon. Vim 9 has a new version of Vimscript (called Vim9script) which Neovim doesn't support, and its APIs for things like async jobs are also different. However Vimscript itself will probably remain a common denominator for many years to come.
TJ DeVries (one of the Neovim contributors, and a frequent streamer) was working on some sort of vim9 translation support for Neovim. Seems more like a side project rather than something that will be built into Neovim, though.
If it's called VimConf, I could understand including content from anything vim related, even vi or neovim stuff (or from the other forks/variations/bases).
But if it's called NeovimConf, I wouldn't expect that to include the entire Vi ecosystem.