apply_filters( "update_{$meta_type}_metadata", null|bool $check, int $object_id, string $meta_key, mixed $meta_value, mixed $prev_value )

More Information

• This filter is applied before a metadata gets updated; it allows short-circuiting the updating of metadata of a specific type by returning a non-null value.
• The dynamic portion of the hook, $meta_type, refers to the meta object type. For example, if a ‘user’ metadata gets updated, the hook would be ‘update_user_metadata‘.
• The filter must return a null value (the value of $check) if the data is be saved to the database. If it returns anything else, the ‘update_metadata‘ function (and therefore the ‘update_{$meta_type}_metadata‘ filter) will return what the filter callbacks return.