Activation possible on PC with old parts that have already been used?

From the Q&A:
"bought a new computer. How do I deactivate the licence on the old one?
You can deactivate the old computer in the user area. After logging in, click on the "Manage activations" link.

Only deactivate computers you no longer use. Once you deactivate a certain computer, you will no longer be able to activate it again, even if you reformat or change operating system."

To me this sounds too harsh, too final. Mistakes can be made, and motherboards can die.   Perhaps in the event of rebuilding a PC with some old parts you can talk to support?
I've never tested that.

They do and sometimes they answer. In this case, I don't know if they are too busy and hence are not reading, or if they prefer not to disclose this inner detail. After all, answering the question "what does the license use to figure out if the software should run in demo mode or fully fledged" is information useful for people who may want to run it illegally without purchasing.

My speculation (pure speculation, I have no basis to say this) is the following. If you ask to them they would not tell you what parts are responsible to make it work or not. They would just say something like "you activate normally per user manual and if you encounter problems let us know and we'll assist you to make it work".

I agree, however perhaps it is to prevent people with illicit intention to activate and deactivate continuously the same machine while swapping one component at the time to figure out the license algorithm? Again, just speculation. I suspect that if a customer asks with a reasonable request to re-activate an old computer (by "reasonable" I mean with some justification and not too many times and not too frequently) they would accommodate the request.