What if they don't want to change owners? Why should a global company from Singapore do what US politicians want?
At least the US is trying to protect the privacy of its citizens in this case. The CCP meanwhile required Apple to prevent Airdrop from functioning properly in China in order to stop the spread of information between protest groups.
TikTok can decide to not sell, in which case it's banned, or it can sell, in which case it's not.