I understand the reasons behind removing embedded encription support in Neovim but I must say is one of the features I'm missing once I noticed is gone. It's great to have a plugin like vim-gnupg but for anyone who wants to go for a minimalist solution for this functionality:
augroup gpg_files
autocmd!
autocmd BufReadPre,FileReadPre *.gpg set viminfo=
autocmd BufReadPre,FileReadPre *.gpg set noswapfile noundofile nobackup
autocmd BufRead *.gpg %!gpg -qd %
autocmd BufWriteCmd *.gpg write !gpg --batch --yes -co %
augroup END
I just put this together and seems to work even without the GPG_TTY environment variable.
PS. Of course this is only for an exclusive use of symmetric cipher encryption, which is my use case.