Yes. AIO liquid coolers and dedicated loops are used, especially in a place where having ultra compact servers is a must. There is a reason why this block has inputs and outputs on the sides.
Yeah exotic cooling techniques have also been popular in large scale enterprie setups but recently water cooling very similar to consumer setups has gained a lot of popularity and is expected to become ubiquitous for enterprise setups in the next few years now we're at a point where you can safely and reliably hot plug most components(For quick repairs with low down time). As density increases, particularly at the chip levels with MCMs, water cooling starts to become a necessity. So now MCMs are here for CPUs, enterprise grade water cooling is quickly coming with it.
Here's Hewlett Packard Enterprise' take on it (They go into the hard physical limits of air vs waters thermal density and stuff further down if you're interested in why we can't just make air cooling better): https://www.hpe.com/us/en/insights/...-using-liquid-cooling-in-five-years-1710.html