I don't know who "all" is in the 7/22 edition of Trump's Random Tweets of the Week, but the US Supreme Court has ruled the presidential power to pardon is absolute.
Why Trump feels the need to mention it is beyond me. Maybe it has to do with his daily five-hour consumption of cable news.
Too bad he can't handle a one-hour version of the daily intelligence briefing. I suggest the Director of National Intelligence works with the White House architect and installs a closed-circuit TV cable. Next, find intelligence officers who look like Morning Joe, Fox & Friends, and CNN anchors. Have them alternate between each other to report the daily intelligence briefing. Trump will never notice the difference, and might actually listen to the whole thing.