Not sitting duck but I would say he has close to zero percent chance if he tries to outbox Usyk. Then maybe 10% chance if he takes risks and is comfortable taking a few punches to land one.
There is a counterargument to what you said, sometimes people can't see the forest for the trees and an opinion from an outsider can change a situation entirely. I'm not trying to say these coaches aren't elite level, obviously they are but to dismiss all outsiders opinions would be foolish. At the end of the day it's all information, the key is being able to discern between the horse**** and useful information.
Problem is he doesn't have a great chin to begin with. His best bet is to use a jab to keep Usyk at range and try to catch him with a counter coming in. Attempting to walk him down will get him stopped.