I think the plea deals at least in Federal cases are not a sure thing. They make recommendations to a judge. But yes any confession will be accepted on its own merit whether or not your "deal" goes through.

That's the problem here. In order to get the deal, the guy had to not only confess, but confess in front of the judge, apologize to the judge, declare stuff about Donald Trump and the 2020 election, read several leftist books, and he assumed he would get the deal the prosecutor recommended. And he didn't. The judge literally stood there and said that he understood what the Shaman said, he believed him, he said it was genuine... but the guy had to have an example made out of him, so he couldn't just let him get away with only 20 some months in a federal prison and doubled his fucking sentence.