I imagine so too. You’ll be able to interate over the users in order and hit an instant index on contact method.

    select
      *
    from
      user
    where
      exists (
        select
          true
        from
          contact_method cm
        where
          cm.contact_id = contact.id
          and cm.method = 'phone'
          and cm.primary
      )
    order by
      created_at desc
    limit 10

    —- partial index is even faster
    create index primary_phone on contact_method (contact_id) where method = 'phone' and primary;