I joined the server and asked around, I haven't spoken to therealcrypt yet but there seems to be some confusion amongst the others as well. I think it was just a misinterpretation. Both the Xbox One and Xbox One X use GPU's similar to PC counterparts, so the performance difference between the two consoles should be pretty similar to that of the difference between the PC versions.

That being said, I might have 1 theory about why the original Xbox One might actually perform as well as the Xbox One X for mining. Since cryptonote currencies are more memory reliant than other cryptocurrencies, the original Xbox One had 32 MB of high speed ESRAM to make up for the shortcomings of its DDR3 RAM before the Xbox One X switched to GDDR5. Since the Xbox One X is obviously optimized for gaming performance, and since gaming performance doesn't translate to mining performance, it's possible the ESRAM in the original Xbox One gives it such a good boost while the Xbox One X is more like a traditional graphics card so its hashrate is where we expect it to be.

But still, to give it such a huge boost that it's nearly equivalent to the Xbox One X? It still seems unlikely even with my ESRAM theory. I think most likely it was just some confusion or misinterpretation. He was probably referring to the CPU's between the two systems having the same performance. In fact, in my own browser based JavaScript mining on my Xbox One consoles, the original Xbox One actually got slightly, but consistently better hashrates than the Xbox One X CPU. It was really weird and I had no explanation for it. So if the original Xbox One could somehow pull off better CPU mining hashrate than the Xbox One X, then maybe GPU mining on the original Xbox One will surprise me too!