You want the good news or the bad news? The good news is that Walmart is giving away two free months of Xbox Game Pass Ultimate right now, but the bad news is that the codes are only applicable for "new" XGP Ultimate members.
This is the same Walmart Plus offer we saw last year, and the smallprint seems to be pretty much the same too. Codes are available until July 2nd, 2024 (or until they run out), and they're limited to one per-customer.
Something to keep in mind is when it says "new" Xbox Game Pass Ultimate members, that seems to mean Xbox players who don't have an active Game Pass subscription right now. Don't quote us on this (because we haven't tested it!), but we're assuming if you're not currently subscribed to Game Pass, this code should work for you.
Anyway, a deal's a deal, even if the new subscriber thing is an annoying catch. It's great for non-XGP members at least!