That claim only deals with Haswell since before that, there was no fuse to prevent running unsigned BIOS code (also known as Intel Boot Guard). Since there are

That claim only deals with Haswell since before that, there was no fuse to prevent running unsigned BIOS code (also known as Intel Boot Guard). Since there are Haswell Chromebooks, there are devices on the market that also provide this feature. The limitation for libreboot devices using recent Intel chips is the ME firmware which is always signed, but not on the CPU and not BIOS code. So the statement is technically correct - through some _very_ careful choice of words.