Unlikely but yes, always be careful: perhaps bring a friend or colleague the first time, or pick a public park you know well, meeting during daylight hours, tell several friends or colleagues where you are going, etc.
Most of all, enjoy, hope you can get a game going!
Badminton is popular with girls, hence red flags. Had it been an offer to play a man’s sport (generally) like football or wrestling, it would have been less suspicious.
Post work? My office ends at 11PM daily. Where exactly will be the badminton court which accommodates lawyers late night schedules.
Most of all, enjoy, hope you can get a game going!