Last year we deprecated the use of GET requests to /sentry with requestType of 1 (token) or 2 (auth) for security reasons. We believe that all production apps that used to do this have since migrated to use POST requests instead, and so we are preparing to disable this kind of request altogether since it should have no impact on current running applications.
We plan to make this change on Wednesday 16th January. If you own an application with bespoke SSO integration you may wish to test login after 11.30am to make sure it works for you, and get in touch with us through helpdesk if there are any issues.