No one said they are M chips. These would be custom made for servers and AI inferencing. Also note their "ARM based SoC" has a GPU with 800 GB/sec bandwidth in the M2 Ultra.
>These data centers will also run completely on Apple’s M chips
That guy is just some random blogger and I wouldn't take that to literally mean they use the same chips as a Macbook. Apple only says they use "Apple Silicon". Common sense to assume it is designed for servers and AI inferencing.