Under a million kids moving over to RedNote for a week or 2 means nothing. There is no whack a mole. Tiktok algo is the sauce, nothing else has the sauce. People enjoyed the sauce.
Tiktok algo is nothing special: https://www.nytimes.com/2021/12/05/business/media/tiktok-alg...
The volume of interaction data from good interface design and huge user base is the core of the success.
Using Chinese social media is cool now.
Fortunately, I think you're wrong about this. American children will be saying mandarin catchphrases before they start using Instagram Reels.
What makes you think the Bytedance chefs who cooked the sauce wont join the Redbook company? Their HQ were both located in China anyway.
And yes, this begs the question of "when does something become a matter of national security". 10 million? A million moving over before the day of reckoning isn't a small thing.