playbook.yaml

---
- hosts: all
  become: yes
  vars_files:
   - var.yaml
  tasks:
   - name: add a admin group
     group: name=admin state=present

   - name: add a new user
     user:
       name: "{{ item.name }}"
       uid: "{{ item.uid}}"
       password: "{{ item.password | password_hash('sha512') }}"
       group: admin
       groups: wheel
       state: present
     with_items:
       - "{{ users }}"

   - name: mkdir .ssh
     file:
       path: /home/{{ item.name }}/.ssh/
       state: directory
       owner: "{{ item.name }}"
       group: admin
       mode: 0700
     with_items:
       - "{{ users }}"

   - name: add authorized_key
     authorized_key:
       user: "{{ item.name }}"
       key: "{{ lookup('file', '/home/vagrant/ansible/ansible_useradd/publickey/{{ item.name }}/id_rsa.pub') }}"
     with_items:
       - "{{ users }}"

var.yaml

users:
  - { name: 'hoge1', uid: '1011', password: 'password' }
  - { name: 'hoge2', uid: '1012', password: 'password'  }
  - { name: 'hoge3', uid: '1013',  password: 'password'}
  - { name: 'hoge4', uid: '1014', password: 'password' }

I've added this to my playbook. It will remove users if its a revoked user and the file exists:

- name: Get stat about public key
  stat:
    path: "{{ lookup('file','public_key/{{ item.name }}/id_rsa.pub') }}"
  register: pubkey
  with_items:
   - "{{ users }}"

- name: remove revoked authorized_key
  authorized_key:
    user: "{{ item.name }}"
    key: "{{ lookup('file','public_key/{{ item.name }}/id_rsa.pub') }}"
  with_items:
   - "{{ revoked_users }}"
  when: pubkey.results[0].stat.exists 


- name: remove revoked users
  user:
    name: "{{ item.name }}"
    uid: "{{ item.uid }}"
    state: absent
  with_items:
   - "{{ revoked_users }}"
  when: pubkey.results[0].stat.exists