What Campbell "wants" is irrelevant. BY RULE, the reporting eligible receiver is announced to the defense. There was literally no way for him to keep that information from the defense.
Not sure why this is so hard for you to understand.
The other piece of this is that who is eligible and who is not is dictated by the alignment. The only reason they announce it in these cases is because there is now an ineligible number lined up in an eligible receivers spot. Somebody in the back 7 should have been wondering why an ineligible number was lined up in an eligible spot on the line. Maybe they did and assumed it was a jumbo run play, which is why they announce it to the defense, like they did.
You can criticize Campbell for the logic but you can't call him unethical.