Jira Request URL Change for OAuth 2.0 (3LO) Apps

[Service Account]

There has been some updates in the OAuth 2.0 (3LO) apps 
Earlier we were using https://your-domain.atlassian.net which is not working when we are trying to access the APIs using the OAuth credentials from newly created App in developer console, it fails with 401 Unauthorized (but it works fine with previously created OAuth app) whereas any newly created OAuth app in JIRA developer console requires the request URL as https://api.atlassian.com/ex/jira/{cloudid}/{api}. 

1. Is the new request URL completely replaces the old one?
2. When did this change happened?