Surprising that there's still that much efficiency to be squeezed out of internal combustion engines!
The military might want it for drones. Even if it's only good for an hour, that's a good survival time in modern combat.
Higher wear is what they care less about: at peacetime, parts can be replaced more often, and at wartime, many will be destroyed before spending up the spec-dictated operation hours.
The issue with the parts isn't higher wear, it's simplicity. Look at the strain that Ukraine has put on military supply chains. Now take a look at what's involved in building a diesel engine versus a rotary. The rotary engine is a few relatively simple castings*, a piston engine has a ton of small, complex parts. There's no mention if they comparable diesels are two or four stroke, but take a look at a four stroke injection pump and how complex they are (inline pumps are basically mini piston engines). Then take a look at the LiquidPiston motor – at least on one variant they're using the crankshaft for fuel and air delivery. Pretty much everything about it is simpler than a comparable piston engine, and when you've gotta scale up wartime production simpler is better.
* okay so it looks like LiquidPiston is milling everything for the time being.
Delivering fuel and lubrication via the crankshaft is not uncommon in aircraft motors, or was at times of WWII at least. Delivering air this way is indeed novel and impressive.
If I'm not mistaken there are no apex seals in there – so there's one major weakness eliminated. Regardless of military applications there is some real interesting engineering there.