Why does Cognito's authorization endpoint support both `/authorize` and `/oauth2/authorize` ?

I am trying to add a user to the Cognito user pool. When accessing the authorization endpoint from the Cognito host UI, the request was sent to /oauth2/authorize. This is the correct path as shown in the documentation at the following URL

https://docs.aws.amazon.com/cognito/latest/developerguide/authorization-endpoint.html

Now we tried to send the request without going through the UI, by typing the URL of the authorization endpoint directly in the address bar of the browser. This time, I converted the path from /oauth2/authorize to /authorize and used the same parameters as before, and the same behavior was confirmed: the redirect response to the authorization screen was successfully returned.

Why do you support both /oauth2/authorize and /auhorize? I checked the past documentation and can't find any mention of it being /authorize before, so I am assuming that backward compatibility is not the reason.

If anyone knows the reason, please let me know. Thank you in advance.