The actual app name would be good to have. Understandable they don’t want to throw them under the bus but it’s just delaying taking action by not revealing what app/service this was.
I was trying to look it up (basically https://developers.google.com/identity/protocols/oauth2/java... -- the consent screen shows the app name) but it now says "Error 401: invalid_client; The OAuth client was not found." so it was probably deleted by the oauth client owner.