As for where Vim was born, hardly matters, it was someone with UNIX culture background, that happened to own an Amiga.
I think they mean MicroEmacs. Despite its name, it was not Emacs, but it had Emacs-like keyboard shortcuts, multiple buffers, and macros, which was quite neat for a free 1986 application on a home computer.
As the sibling comment points out, MicroEmacs isn't really Emacs.
Also Emacs history is older than UNIX, and overlaps with Lisp Machines.