Water is neither created nor destroyed.
Being neither an element nor a noble gas, that's actually not true. In the context of the article, since they're talking neither about hydrolysis nor reacting anything with it, you're right that there's no actual
destruction of water. That's obviously not the point, though.
What do they mean when they say water is used?
Evaporated (i.e. so it's no longer available for other uses).
Evaporation means it precipitates as rain again so it's not really wasted.
It's wasted if you evaporate it in a place where water is scarce and in high demand, but it rains down somewhere where it isn't. If the datacenter is somewhere arid, where water scarity tends to be a problem, then it's almost guaranteed that there won't be precipitation in the vicinity. Even if it does precipitate nearby, you can get a phenomenon called virga, where the rain evaporates before it even reaches the ground. While hiking in the mountains of Colorado and New Mexico, I've seen this with my own eyes.
en.wikipedia.org
Whether the water usage quoted in the article is a problem depends entirely on
where the datacenter is located. If we were talking about the Colorado River basin, then every drop of water to be found is
already overcomitted.