I think so if you set up your account with your ms account. I did the same thing and it was able to activate no problem automatically if I reinstalled. You should be able to log into your office 365 account and you should be able to see your licenses in there, I just don’t remember where lol

First, the key being tied to the motherboard is more specifically when you purchase a prebuilt machine and not an off the shelf license.

Second, Microsoft is pushing heavily at tying the keys to a Microsoft account. That way they can more easily track number of activations. To recover a key on a new computer you just sign into your Microsoft account and it’ll activate it. It’s far easier than a key and easier to keep track of vs a key as well.

You might be able to buy a license at a large retailer, but I’m pretty sure you’ll find it hard to buy a key printed on a piece of paper now.