You're statement is true, would should not do the same thing in terms of discrimination, but the two situations are a bit different. Your talking about culture, while this deals more with a outside government's influence on our populace.
For me, think the ACLU makes a valid argument, that this could set a bad precedent. But, the Chinese government already has a system to at least partially monitor and influence what some businesses do (requiring corporations to have role for the CCP in their charters). https://www.csis.org/analysis/new-challenge-communist-corpor.... It doesn't seem out of the realm of possibility that the CCP uses tik-tok to influence the US populace (think Russia and its use of social media during the 2016 election of Trump).
Yeah, this situation is pretty messy.