I haven't taken an incredibly close look at this, but it seems like a pretty bad idea. Elisp is definitely not a great language, and I'd like an alternative as much as the next Emacs user. But I feel pretty strongly that any alternative has to be a Lisp, or very close to one. Code-is-data/data-is-code is very important for the more "config-file" aspects of configuring Emacs. Being able to use and write DSLs to succinctly encode exactly how you want aspects of the editor to behave is a critical strength. I've tried systems that were configurable in Python and other good-but-non-Lisp languages, and it's always much more annoying, because the language is (purposefully) limited w.r.t metaprogramming and possible DSLs. That's a good thing when optimizing for maintainability by others and obviousness, but not so much when optimizing for maximum personal customizability.
Go seems like quite possibly the polar opposite of this, as far in the "keep it simple and understandable by literally everyone by cutting out many techniques for metaprograming and code reuse". Which perhaps is the point, but if so it seems like that point misses much of the draw of Emacs?
While this is definitely impressive technically, I think Guile Emacs is a much more plausible option.
I used Emacs Lisp for scripting tasks like code and data generation. It is great to have an ability to evaluate form right inside the spot you want results to be inserted. This kind of code does not require AST manipulations or macro.
Also, some of my projects that become bigger than 1000 LoC could benefit from static typing and (subjectively) better tooling.
By the way, I think extending Emacs in Racket would be great; just do not have an idea on how to implement that integration smoothly.
You may already know about Guile-Emacs, but in case not, take a look at https://www.emacswiki.org/emacs/GuileEmacs . Guile is not Racket, or more precisely Racket is no longer exactly Scheme, but they are closer to each other than to elisp.
I use elisp for scripting occasionally (very handy when you need to script on some server but the administrator does not want to install a Lisp compiler, and quite usable with the cl- libraries), and the biggest annoyance is that you need to use buffers to do file IO. That is another layer of boilerplate on top of the Lisp file IO facilities, compared to Bourne shell-style scripting.
Racket seems like a near perfect match for the domain. Start with a hacky one-off script. Augment with unit tests. Code base grows and starts becoming more stable? Progressively migrate to Typed Racket.
Go seems like quite possibly the polar opposite of this, as far in the "keep it simple and understandable by literally everyone by cutting out many techniques for metaprograming and code reuse". Which perhaps is the point, but if so it seems like that point misses much of the draw of Emacs?
While this is definitely impressive technically, I think Guile Emacs is a much more plausible option.