Of course this is very good news, however they were released without bail, which sends a slightly different message. Many probably were prepared with fake IDs and will not show up for trial.
No doubt they will all demand jury trial, knowing that would back up the system and that one rogue juror could keep them from a conviction. In DC the chances of that are unfortunately very high.
Then, even if they are convicted, the DC Superior Court judges are all far left nutcase liberals. There is no way they are sentencing these thugs to jail time. The WashPost recently ran a series on an idiotic law they have here which effectively releases young first time offenders, even for serious violent crimes. Many have gone on to commit more violent ctimes, even murder. So these people not only are unlikely to see jail, they will likely get their records scrubbed after some minimal probation.