https://thenextweb.com/business/2019/05/17/google-isnt-killing-off-nest-integrations-just-yet/

Google predictably strirred up a hornet’s nest when it announced at its annual developers conference that it would be shutting down the Works with Nest (WWN) program on August 31, 2019.

This would have led to all existing Nest integrations not working beyond that date, in addition to forcing existing Nest customers to migrate their accounts to Google accounts and use Google Assistant to control their smart home setups.