How can it be abuse? If 2 months leave is part of package then surely it's up to them how they use it. You wouldn't criticize them for using all the money they get paid would you?
That means the team was down an engineer for basically an entire quarter, without notice. That wrecks schedules and causes headaches for your coworkers who now have to figure out how to make up for the lost time or figure out what work to cut from the schedule.