When I first read the email, just after 6 a.m. on March 16, I couldn’t quite believe what I had seen. I was still waking up, so wondered if I was dreaming it. But it turned out to be true.

The subject line, “‘TikTok Master Messaging’ Document,” made me anticipate something altogether different. Occasionally, I’ll get barely literate messages from angry old men — and they are always men — pointing out my folly in trusting TikTok, which they consider a Chinese puppet company.

But this was different. This was a message from a staff member working on the House Committee on Energy and Commerce, which will be quizzing Shou Zi Chew, TikTok’s CEO, live and in person this Thursday.…