According to Burdick v. United States, a pardon carries an imputation of guilt and that accepting one carries a confession of guilt. Doesn't need to be specific. Nixon was blatantly confessing that he was indeed a crook when he accepted the pardon.
Like everything with Trump, that doesn't matter.
He'll sign whatever he needs to sign, then he'll release a stupid fucking video like yesterday or do another hate rally and say he's completely innocent -- maybe the most innocent president in history -- and that he wasn't going to pardon himself until a man came up to him, big burly man straight out of central casting, with tears in his eyes and said "Mr. President, if you don't pardon yourself, the country can never heal and the deep state won't stop until they punish you for making America great." So he's not doing it for himself, nope, his presidency was very beautiful and perfect, he's really doing it for *us* and he loves us and we're very special.
The rational among us obviously know that's bullshit and will be outraged, and the cult with either believe him or won't give a shit because of the lib tears. So, same as it's been for the last four years.