I disagree, and I think your reasoning is off. If the raid didn’t kill Osama, why would anyone have sanctioned SEAL Team Six? No, their death is the proof they got the right guy.
Or proof that they found out they got a double or someone else and it was all a sham. They knew it was a sham.
In my opinion, if the dead guy was a substitute and Team Seal 6 discovered the fake, someone had them eliminated so they couldn’t release the information.