You will handle it just like every tough, tenacious and resilient parent and human being. Gen Z won't be the only one losing their once beloved heroes and idols. Unfortunately, all living generations are capable of not handling such news.
I firmly believe this is why it has taken so long and part of the plan. Not necessarily because of the physical war itself, but the preparation of public disclosure of these evil people and the immediate fallout from it. Systems have to be in place in order to support the extreme reactions from the masses. Uplifting policies and news will replace the depression on lots of people's minds.
When financial, health and careers are looking positive, evil entertainers and fake heroes will be yesterdays news as people look forward to the future.
This happening, whether we like it or not. Can't have change without change.