So some fun facts:

• If you buy enough licenses from Microsoft, instead of giving you a bunch of unique licence keys to keep track of, they will give you a license that you can install on a server, and a special “volume license key” that you use on every machine - then, instead of talking to Microsoft to activate themselves, they connect to your server which ensures that it is only activating as many machines as you have licenses for
• These volume license keys are public knowledge to the point that Microsoft publish them on their site because they are useless unless you have a server to validate the activations
• The server protocol is not complex, has been reverse engineered, and there are open source server implementations that forget the whole “ensure you have the right number of licenses” part

Just in case it doesn’t carry over, run this first to get your Windows Pro key: https://www.nirsoft.net/utils/product_cd_key_viewer.html

massgrave.dev

Not at all, Windows 10 and beyond identify your hardware composition, so as long as you don’t swap the mainboard, the license is automatically applied again upon internet connection (assuming you install the same windows version and do not enter another license key during installation). If you want to transfer your data though, get a cheap external USB HDD enclosure and use clonezilla to clone the drive. Edit: typos

If you install fresh using a USB created by the Media Creation Tool, there is one detail you’ll need to know. The install/OOBE setup will still prompt you to enter a key and activate. Just tell it to skip for now/activate later. Once it finishes and goes online, it will activate automatically.

If you’re replacing, why not clone the old drive to the new and expand to fill?