Question about the example on MetricFlow in dbt docs

The problem I’m having

Understanding how MetricFlow:s semantic layer work

Is the example in the dbt docs correct?

The example states:

“Imagine an even more complex metric is needed, like the amount of money earned each day from food orders from returning customers.

The metric is defined as:

metrics:
  - name: food_order_pct_of_order_total
    description: Revenue from food orders in each store
    label: "Food % of Order Total"
    type: ratio
    type_params:
      numerator: food_order
      denominator: active_customers
    filter: |
      {{ Dimension('customer__is_new_customer')}} = true

Returning customers are not new customers. Ought it not be?

{{ Dimension(‘customer__is_new_customer’)}} = false