But a guess can be wrong. As somebody from Eastern Europe many other events come to my mind first in relation with 1989.

And why would that be in any way relevant to an article about a Chinese ad targeting other Chinese in China?

Contextually it's more than obvious for anyone even casually familiar with Chinese history which the audience would be.

Or the fall of the berlin wall, depending on context.

For reference, that is 9 November 1989.

Yes, I'm aware, was just pointing out the 'in 1989' part has 2 distinct cultural-landmark events for me

I gave the specific date so people can see the date for both in this thread.

I could place it with only +- 15 years if I’m going to be honest.