According to the specification, CIE code alignment factor is an arbitrary unsigned LEB128 encoded value.
Even though the blog post from Ian Lance Taylor says that "... should always be 1 for .eh_frame." there is no such thing in the standard and both ld and gold allow arbitrary code alignment factor. Hence, there is no reason lld should enforce the value to be 1.
Furthermore, this breaks while linking objects on some platforms; for example the binutils assembler uses code alignment 4 when emitting the CFI on arm64 which is the most sensible thing to use, since instructions are always 4-byte aligned.