The :disabled keyword inhibits loading a package, and all its
customizations. It is equivalent to commenting out or deleting the
definition.
You could use this, for example, to temporarily disable a package that you’re having difficulties with, or to avoid loading a package that you’re not currently using.
This example disables the ‘foo’ package:
(use-package foo :disabled)
When byte-compiling your init file, use-package omits disabled declarations from the output entirely, in order to make Emacs startup faster.