It's different, but I wouldn't say hack. Looks like a cue somebody built while still learning. The insert in the butt was likely intended to help ensure the pin went in center, and/or ensure the pilot on the shaft fit into the butt center. Even if the pin is not center in the butt, it is center in the insert, which means the insert on the shaft will fit clean. If there was no insert in the butt and then pin was off center, then the piloted insert on the shaft wouldn't fit well into the butt. So to me, it seems like a clever way of ensuring the piloted joint fit together correctly. It also tells me that in order to add the extra step, the builder (at the time) was not confident that he could get the pin centered. But at least he did find a way to correct the problem, or at least gave the effort.
Guessing by the phenolic color, the cue is 10 years or older. Just a guess. That phenolic isn't readily available & hasn't been for a long time. Again, seeing that the insert appears to be a solution to a problem, I would say it was done by a hack, but rather likely by somebody learning. Hacks either don't notice or don't care about quality. This guy obviously does/did. I'd be curious to know who built it.
edit: If you want shafts, try Ryan at Meullers. He can make a shaft for it....though i'd be hard pressed to think of anybody that still has phenolic that will match that cue. That was the good stuff. Not like that anymore.