I don't know about use of the store in general, but if you use the MS store to buy a Windows license they automatically convert your account and link the licens

I don't know about use of the store in general, but if you use the MS store to buy a Windows license they automatically convert your account and link the license to that account. Source: built a new PC a few weeks ago and naively assumed they'd just give me a product key or ask how I wanted to receive it.