@mbcladwell guile-next has it, I use it. The problem can be in some other place. How do you run ares?
You don't need to specify #:port if you use recent emacs-arei, it automatically picks the port from .nrepl-port file.
I use 7888 in ares local checkout only because I need a quick connect capabilites from other places, where .nrepl-port is not present (for test.scm from arei project for example).
For all other projects I use a random port.
@mbcladwell One of the reasons we don't release Arei 1.0 is because guile is not yet updated in guix, so it requires some hussle to setup correctly: rebuilding guix and other packages with guile-next to work with ares, carefully setting apropriate load paths and so on.