This is partly correct. You can replace the touch id sensor, but you will lose the ability to use the fingerprint. I think it depends on if you encrypted your disk if you might be able to just reinstall it, but I have not read that you cannot do it, just that fingerprint unlock is not possible.
There is a specific chip in it that binds it to the board.
With the right equipment you could perhaps transfer it, but that is high level skill - check out Rewa if you’re interested, they do that for some parts and have videos.[br]
It's something I personally skip on - and on Apple products all together because of the horrors of repairing them. [br]
[br]
If indeed the board does not work at all without the flex cable, then the cable has the chip on it.
Since I have seen these boards boot without it attached, I cannot imagine it will not work at all, but if that is the case, please be very specific in the how and why before you claim it. Thank you.