Taxonomy phrases can nonetheless be added when solely assign_terms functionality has been granted

I am setting the capabilities for a taxonomy with the under:

$assoc_tax->capabilities['manage_terms'] = "zzz";
$assoc_tax->capabilities['edit_terms'] = "zzz";
$assoc_tax->capabilities['delete_terms'] = "zzz";
$assoc_tax->capabilities['assign_terms'] = "edit_posts";

And registering with:

register_taxonomy( 'affiliation', ['activity', 'job'], $assoc_tax );

The place exercise and job are two CPT’s.

When including a brand new CPT the person remains to be allowed so as to add new phrases for this taxonomy, and it seems as if that shouldn’t be the case.

Am I doing one thing clearly flawed, or lacking one thing?