Hi Wei,
Could you confirm what you meant by removed? As per checking your client account (492-651-8637) in the Google Ads UI, I can see that it still has the MCC account (585-184-8752) as one of its managers. That being said, the ACTIVE status that you are getting is correct as it means that the link between the client account and the MCC account still exists.
The red icon that you are seeing next to the client account's ID means that no ads are currently serving and means that the account itself is INACTIVE (campaigns and ad groups have been paused). However, this type of status is currently not returned via the Google Ads API. To learn more about inactive accounts, you may refer to this blog post. Let me know if this helps.
Thanks and regards,
Peter
Google Ads API Team