It's important that at least some in Europe hear the message. The more often it is repeated, the more likely it is that at least some of them will hear despite the censorship and misrepresentation of Chinese officials in western media. Spain has already heard it because they have their own problem with separatism. Explaining to the rest of them that China will fight with the same or more determination as Ukraine will teach them that it's risky to promote separatism and remind them that this is China's red line over which it would be forced to go to war.
And should an actual war in the Taiwan straits break out anyway, some countries will remember the message and may not impose sanctions or will be very slow to do so compared with a situation where they only listen to their media bubble which tells them that Taiwan is a sovereign state.
Wang Yi clearly linked the Taiwan and Ukraine questions at the Munich security conference when demanding that there should be no double standards regarding the respect for territorial integrity
