bug#38101: User's customization to completion-styles requires tweak to completion-category-defaults

[João Távora]

> >     (setq completion-styles '(flex))
> >     (setq completion-category-defaults nil )
>
> Ha, I was just thinking about that: could you open a bug report about
> the need for tweaking completion-category-defaults?
> Note: the above `setq` isn't enough because packages can (and do) add
> themselves to completion-category-defaults later on.
>
>         Stefan

Hi maintainers,

As you can read in the above conversation, completion-category-defaults
needs to be tweaked to "unshadow" the user's customization to
completion-styles.

This is a bug report to track any possible improvements that can be done
in this regard.

João