Must I use a MS account before OS reinstallation or it wont activate?

My aunt bought a used Windows 10 laptop, OEM licence. Correct me if I'm wrong, but I believe this is legal, since a OEM licence is tied to a particular device, so one can sell their copy of Windows as long as they also sell the device? (that is, it is legal for my aunt to use this Windows laptop?)

Because the laptop is used, to be on the safe side, I asked my aunt for permission to do a clean OS reinstall. It seems reasonable for me to wipe the disk and do a clean OS reinstall if buying a used computer.

However, there is one thing that stops me. From the article Reinstall Windows 10 on support.microsoft.com:

In Windows 10 (version 1607 or later), you must link your Microsoft account to the Windows 10 digital license on your PC before you can reactivate Windows.

Wait, what? After version 1607 it is not enough for Windows to take the activation key from the motherboard, as it used to be? If I simply wipe the disk and reinstall Windows it won't activate, I MUST first create a Microsoft account and link it to the system before wiping the disk? So I need to connect to the internet a system that contains who-knows-what and use it to set up an account?

Inspection of the bought system revealed that it only has one local account and is not linked to any Microsoft account. Good - it seems that connecting the licence to a new Microsoft account is possible. Nonetheless, I would like to avoid it if possible, for the following reasons:

1. Perhaps I'm exaggerating, but again, I have doubts about connecting to the internet a system that contains who-knows-what and use it to set up an account;
2. The computer belongs to my aunt and not to me and as far as I'm aware my aunt is VERY strict with not providing her personal data to anyone if possible and, as far as I'm aware, Microsoft accounts now require a phone number;
3. Really, is it now necessary to have an internet connection and provide a phone number to Microsoft to use a computer because else the system won't activate? This seems kind of ridiculous to me.

But running winver in the bought computer revealed windows version 2004, build 19041.329, which is newer than 1607. Also the laptop seems fairly recent so it seems probable that the laptop's manufacturer preinstalled a Windows version newer than 1607 in the first place.

Do I have to set up a Microsoft account and link it to this computer before reinstalling the OS?

Hi kmph. Welcome to Tenforums @kmph

No you do not have to link account, helps if you are making big changes to device.

Here is our clean install tutorial. When you get to step 23 skip it and go to step 24. Use a generic user name if selling.

Clean Install Windows 10

Setup uses /Sources/gatherosstate.exe to create a Genuine Ticket for that PC which is used for Activation

Megahertz said:

As already mentioned on the above posts, all you have to do is a Clean Install Windows 10 (deleting all partitions).
If I were you, instead of ver 2004 I would install ver 1909.
2004: Worst Update Ever
Known and Resolved issues for Windows 10 May 2020 Update version 2004

2004 is a fine update - a few glitches but nothing serious. Compare that with some that deleted files, or earlier ones that remove partitions. It nowhere near qualifies as the worst update!

There is so much BS FUD spread about 2004, it is unreal. The biggest complaint is users are getting told their pc is not compatible.

So if MS upgrade somebody and it does not work, they get slated. If they do not upgrade somebody because of potential issues, they get slated. They are in a no win situation.