The whole TOS thing was silly as well. Emergency patch with a TOS and done. Sure, on Apple's AppStore and maybe Google's store it would take like a week. Every other platform is pretty much instant.
I don't think that would work. If their original terms weren't stating an age restriction and essentially permitted kids younger than 13 to sign up, then adding a new ToS doesn't retroactively apply to the existing user's past activities. In other words, all past activity would be subject to potential fines regardless of what the current ToS says. Now, any new activity would be covered under the ToS once the user agrees to it. That doesn't mean the kids would go away, but it means that Piper Chat would have no longer been held liable if the user broke the ToS.
Also, they were put in a quandary about updating the ToS. If they updated it,
someone would probably notice, and they'd also check to see what's new. (A brash new start-up would likely be under the eyes of competitors, like Hooli.) In other words, by updating the ToS, they may end up inadvertedly alerting the authorities... .
Essentially, they were screwed no matter what they did... until they no longer had the company.