The tweet's saying the govt isn't going after Tornado Cash. They've said they won't appeal the court decision. Roman Storm isn't free he's going to court because they're saying he knew his mixer laundered money so his case's continuing.
He didn't say Tornado Cash devs should be convicted for money laundering. When Biden was president American laws didn't show they were friendly to crypto. Trump's showing he wants to help crypto. We'll know if Roman Storm's free or guilty after the court judgment.
I am no proper follower of laws regarding money laundering, but if they won't go after the Tornado Cash (meaning the sanctions were dropped) then the devs might as well at some point see freedom. Arresting developers for just developing a software was already looking bad because it's not them that laundered the money or asked the Lazarus Group to use the platform.