Werner Zeh has abandoned this change. ( https://review.coreboot.org/c/coreboot/+/81678?usp=email )
Change subject: src/arch/x86/bootblock.ld: Preserve space for the .init section ......................................................................
Abandoned
Turned out that the issue I was seeing was caused by the old linker 2.37 (coreboot toolchain from 2022) and it indeed is an error in ld. The patch that fixes it in ld is can be found in [1].
TLDR: ld has evaluated SIZEOF() wrong as zero under certain conditions which then led to a wrongly placed .text-section in the bootblock which then caused the overlap with the section .init.
Switching just ld to the new version 2.42 (while keep the rest of the tools untouched at the state of 2022) fixes the issue reliably.
[1]: https://github.com/bminor/binutils-gdb/commit/648f6099d4dcadf446f3f00790ad4b...