At the risk of going off on a tangent about that maxim; I feel like it's just misusing the word "purpose".

Maybe it would be cleaner to state that a system has no purpose (at least not until it is sentient), instead it has behaviors. Then one can observe that the purpose of the designers or maintainers of a system simply happens to be at odds (or as AI safety researchers would say, are "out of alignment with") the behavior of the system.

That all of course presupposes that one can accurately deduce the purposes of the designers/maintainers.. In the case of TikTok, I'd bet that we are all in agreement that their purpose is nothing more nor less than maximal value-extraction from people wishing to express themselves with videos multiplied against an audience of people who wish to view videos multiplied again against advertisers who want to insert propaganda into eyeballs.