I imagine that might be in response to the malware advertising that was going on for fortnite a while back, and how quite a large proportion of the players are kids. As a highly visible brand and a highly vulnerable audience, it makes sense for them to focus efforts there and put in special rules.

I think you are correct in why they put the extra effort in, but the criticism is they should be doing this anyway, for all the ads. Not just because the target audience for a specific keyword is more vulnerable to scams.