That data center likely still uses liquid to liquid heat exchangers with a chilled water loop and cooling towers to reject heat outside, but I could be wrong. Piping refrigerant around a massive building costs way more than chilled water, same goes for filling up the system, glycol and water is cheaper than refrigerant.

That's inevitable, really, given the way power densities have been increasing. I wouldn't be surprised if people weren't also experimenting with high pressure Helium and similar technologies.

It's certainly a far cry from opening some windows and stringing a few fans together in the hope that the chilly outside air will be enough to keep things cool!