There is a different actually (and it's happen to me). If you buy the old windows and upgrade to windows 10, your windows 10 runs without keys. When you having a problem and call microsoft tech support, they can't do much and ask you to reinstall the old windows, reactivate and upgrade back to windows 10. This is all because your windows 10 license are from the upgrade, hence a keyless license. Sometime the old key can't be activate anymore cause they already been upgraded to windows 10 ealier. This is what happen to me and I had to buy a new windows 10 with its key.

If let's say from the start you buy a proper windows 10 with a license key, tech support can help you like a normal day with less steps from your side.

If your company got the budget, go for a retail version instead of oem. Oem version license are tied with the machine motherboard where they been activated, so you can't transfer the windows license to another machine or upgrade/change to a new motherboard later on. Yes, sometimes microsoft tech support said they can help to re-activate the license when you change a damaged motherboard, but most of the time it is bullshit, you will have to buy a new windows key like what happen to me last time when I replace my broken motherboard (but i bought from a cheap seller, they ask to buy a full price license again, they can go to hell).