Badly chosen title and thumbnail aside. It's actually the 2nd reason. With Rust now part of the kernel, the kernel won't build for a number of architectures. Whether the architectures are obscure or not is debatable. I sure wouldn't want to debate one who still uses them though. Either way, the fact that the kernel won't be compiled for these architectures is true.
Badly chosen title and thumbnail aside. It's actually the 2nd reason. With Rust now part of the kernel, the kernel won't build for a number of architectures. Whether the architectures are obscure or not is debatable. I sure wouldn't want to debate one who still uses them though. Either way, the fact that the kernel won't be compiled for these architectures is true.