This happens all the time with used Xbox Ones - explanation (Off-Topic)

by Korny , Dalton, Ga. US. Earth, Sol System, Sunday, December 07, 2014, 21:32 (3641 days ago) @ Mid7night

The Home console setting is enabled by default for the first person who signs in to a new Xbox One. Since yours is used, and you've never gone in to change that setting, it is still the home Xbox of the previous owner. With digital download games, they become available on two systems when purchased - the one where the owner is currently signed in, and any account signed in to the owner's Home console. Whoever you bought your Xbox One from bought a black friday bundle and just redeemed the included games. If you never tell them, you'll get every game they buy digitally for free.

This seems to be the most plausible explanation.

But it's still puzzling...
Would this still happen if the person I bought it from did a system-wipe/restore before selling it to me? He said he did, though I really didn't know how to check, it seemed "fresh" to me. When I booted it up at home it walked me through the whole setup routine and everything. I even registered it on my Xbox account.

Also, it would be exceedingly weird (to me) if I'm getting his digital purchases, because the reason he told me he was selling is because he didn't have time to play. I don't think I have the the guy's contact info saved anywhere anyway. Maybe he changed his mind. :)

Re: "Home console setting"....didn't even know that was a "thing"

You could wipe it a hundred times and it's still registered under his account as the "Home" console (licensing games via console serial number, or something). We had a big annoyance when we tried to put some of my games onto an XBone, since stuff like Killer Instict was downloaded onto a different console. Even setting the new one as the Home did nothing to anyone else who wanted to play my games. It's stupidly frustrating, but I'm glad that buying Xbone games isn't exactly something I'll ever need to do...

I'd tell the guy to contact customer service, because if his kids or whatever ever try to play the games he buys, they won't be able to, because your console is his "Main"... So on the one hand you'll get free games, but on the other, you'll be a pretty big douche...