Indeed, as Group B is not by far as strong as the others, any of the team there could feel "lucky" as everybody has the chance to progress to quarter-finals. But that's it, so everybody should try and capitalize on this situation.
As for Romania, they have the youngest team there and lost some good players and good momentum after surprising at Youth Euro 2019. Some players were not let to go to Japan by their clubs (especially those playing abroad) or lost their "touch" due to injuries or not playing much since 2 years ago. However some of the players were part of this year Youth Euro in Hungary when they did not perform bad in the group matches. There was also a change of coaches at this level as Mirel Radoi became coach of the senior NT but he will still lead the olympic team as Adrian Mutu who coached them in Hungary in March ended his contract.
I am not sure what to hope for but I am sure it will be very very hard after progressing to knock-out stage.