Arkham simply tags addresses just like what bitinfocharts has been doing for years. Both the former's data and UI are more comprehensive than the latter, so it makes sense to use that platform for on-chain sleuthing. You'll have to do most of the tracking yourself or through another tool though.

Re: this miner. If they keep on reusing the address, or keep on applying the same spending patterns, it's likely that we'll learn more about the operation, eventually. Part of me hopes we'll never know. For pools, providing transparency is important - both for their miners as everyone else. But for true solo setups, I wouldn't mind seeing a lot more of these unexplained origins.