The court will be very zealous of its power (from 1803, in Marbury v. Madison) to decide that laws are unconstitutional, so yes, if the court things a statutory codification of Chevron is unconstitutional, they will so rule.
However it's also very unlikely that Congress will pass Chevron into law, and the text they might write might be narrow enough to pass constitutional muster, so until then this is a purely academic question.
However it's also very unlikely that Congress will pass Chevron into law, and the text they might write might be narrow enough to pass constitutional muster, so until then this is a purely academic question.