No they did not, they allowed convicts to join the military under very strict rules. And why not? As far as I can gather from the article the issue is certain members of the unit. And even if the American is found to be an issue, they can discuss with the US what they want. Convict or expell
Letting them out suggests they will be free as well but they are not. They are bound to their unit, and it is not allowed for a lot of crimes. Violent crimes, sex crimes, DUI, and crimes against state security are all excluded. The Ukranian law also for it people that have a criminal record from serving and this also changed that. So it is not a “free pass” but they no longer have to ait in a jailcel eating up state resources.