According engineering this was changed as part of the OpenID compliance.
We will review this and update if needed in a future release.
if you would like to keep the original message for a wrong redirect URL .
You can do the following customization using OTK Customization.
1- Copy the below block from OTK Fail with error message
2- Paste the block within #policy - #OTK Fail with error message as shown below
3- Update the error message in the #policy to invalid_redirect_uri within in the variable error.msg
3- Save & Activate the #policy
Now you have back the original error message .