The idea would to be to create interfaces that users, plugins and/or GUIs could override to provide a unified experience while still being customizable for users.
(and as a self plug, I think we have a lot of interesting ideas in telescope.nvim about UI that could be upstreamed over time)
We want to create interfaces to make this simpler for people to use.
One example is here: https://github.com/mjlbach/neovim-ui which is just in a separate repo to make it easier to work on rather than one huge PR.
This is an extension of the ideas that I started in https://github.com/nvim-lua/popup.nvim and a few other places.
The idea would to be to create interfaces that users, plugins and/or GUIs could override to provide a unified experience while still being customizable for users.
(and as a self plug, I think we have a lot of interesting ideas in telescope.nvim about UI that could be upstreamed over time)