IMO, exwm-input-set-key and exwm-input-set-simuation-key might make sense as autoloads as they might be called from a configuration before enabling EXWM, but I don't feel strongly about that.

In the old exwm-config.el file the variables were set directly, so I think we are safe with not autoloading these commands. There is also the plan to move over to a keymap-based configuration later on.

Otherwise, EXWM needs to be started before any of these functions are called so autoloads make no sense.

Agree.

Not to forget, the fix is easy enough if users want to use EXWM functions earlier for some reason:

(require 'exwm)

For all other users the reduction of autoloads makes it easier to understand how EXWM is supposed to be initialized. Maybe we should also provide a use-package example? I don't use use-package myself anymore, so I am not the best person to provide it, but it will probably have a form like this:

(use-package exwm
  :init
  (exwm-enable)
  :custom
  ...)
(use-package exwm
  :hook (emacs-startup-hook . exwm-enable)
  :custom
  ...)