He'll reduce the sentence to 2 games, but no, he isn't just going to say: we were wrong, sorry guys.
This is the essential problem with the way Goodell runs the Justice Thunder Fist of the NFL Front Office. He wants the league to be the military, with strict codes and punishments and Serious Things Taken Seriously. But it's not. It's a big sloppy sports league. Most on-field stuff should be dealt with by saying "knock it off," but he never says "knock it off," he only says "How dare you!"
And when you deal with every tiny thing by saying "How dare you?!" you end up stepping in it, all the time. You commit a massive amount of resources and money and PR capital to determine whether two guys might have done something that no one has ever cared about, and that investigation completely misreads (willfully or accidentally) the science behind what happened -- which, again, no one knew about, because no one had ever cared about the gameplay issue it affected. But by turning over $5 million worth of legal rocks you discovered some grubby behavior. So you yell "How dare you!" the loudest you've ever yelled it -- because maybe recently some people have pointed out that you didn't really yell "How dare you!" to a couple guys who deserved to be yelled at, and you looked stupid. So you yell, you yell a lot, you yell so loudly that no one will ever be able to accuse you of not yelling!
Then a bunch of reasonable people point out that the science that justified all that yelling might have actually been wrong. This isn't really your fault, necessarily -- because who the fuck ever cared about the Ideal Gas Law in football? Who even knew this was a thing? -- but it still might be wrong. And if the science was wrong, the whole thing is pointless. The $5 million of legal rocks you turned over might all be worthless. All of the Integrity of the Game speeches, all the We Care About Fair Play speeches, all the yelling and yelling and yelling and yelling might have been because the lawyer you paid $5 million never considered that if balls lose pressure in cold air they might gain pressure in warm air, and if the Colts' balls were measured later in the halftime than the Pats' balls they might have more air pressure, oopsie, sorry, but you can't have your $5 million back.
So now what do you do? Well, a normal person with a moderated sense of his self-worth and position in the universe might take a deep breath and say, "You know what? This whole thing was messy, and unfortunate, but at the end of the day, there are simply too many questions about what happened, or didn't happen, and too many issues with the measurements of the footballs -- because we had never, as a league, put in place an official policy to track football air pressure. And ultimately, it doesn't seem fair to levy a massive penalty here, because the process by which we investigated the issue was just too problematic."
That is not what he will do. He will thank Tom Brady for his testimony, and for his New Spirit of Cooperation he will reduce the penalty against him. But he will stand by Wells and the Wells Report. He will say that Wells's work is unimpeachable, his honesty and integrity unquestioned, and his investigation thorough and satisfactory. Because when you are a person who yells "How dare you!" over and over, year after year, you simply cannot all of a sudden take a measured or reasoned response to anything. It isn't possible. The person who yells "How dare you!" all the time just doesn't ever admit his own fallibility in any meaningful way. I would be utterly shocked if that happened.