Errrr no its about being able to speak general English well. Most pilots at CX speak English as a first language, all pilots at CX speak English fluently. Some of our flights are over 15 hours long, what a great time everyone will have if the guy sitting next to you can only understand operational English. What happens when there is a problem in the cabin that requires a discussion?
Yeah ATC online gives you a great picture of how much English you need
Most screw ups with ATC are due to poor English, either on the part of the controller or the pilot. If your English is borderline forget about the ICAO test, you will fail the interview if you can not have a broad conversation, covering technical subjects as well as personal ones. You have to be able to speak fluent English to get a job at CX.