Removing numerous Meta boxes from numerous CPTs

ACF is a great plugin that very well may have these as options, but you might consider registering the custom taxonomies in your theme or plugin the WordPress way.

If it’s an option for you, you’d have a lot of flexibility to do a couple of things.

1. You can register 1 taxonomy for multiple post types
2. You can choose to hide the UI, that way you don’t have to hide it later.

Here’s a simple example modified from the codex for our purposes here:

add_action( 'init', 'create_wpse_tax' );

function create_wpse_tax() {
    register_taxonomy(
        'custom_tax',
        array('cpt_1','cpt_2','cpt_3'), // <- multiple post types in an array here.
        array(
            'label' => __( 'Custom Tax' ),
            'rewrite' => array( 'slug' => 'custom-tax' ),
            'hierarchical' => true,
            'show_ui' => false, // <- don't show the UI
            'hide_meta_box' => true // **EDIT** - don't show the meta box
        )
    );
}

EDIT: I just found another parameter that’s not in the codex called hide_meta_box. This may be more like what you’re looking for rather than completely hiding the UI. See edit in the code block above.