I figure I might have something relevant to putter out since I used to work for Wally's World o' Wonders. I was a Support Manager (fancy title for the hired goon that supervised every hourly employee and did grunt-work the salaried managers didn't want to touch with a ten foot pole). So, I like to think I know a thing or two about a thing or two about how Mr. Sam's horror-house works.
1. Depending on how Chris addressed his/her letter, one of two things happened to it- if it was just to "store management" or some other abstract, vague title, it was probably put in a large collection of unsolicited mail. In my store it was labeled "unknown". During their fifteen minutes of house-keeping, the duty assistant manager of the day probably opened it, took one look at it, and then threw it out going "crank. Can't do anything." Or, if it was actually labeled to a known assistant or store manager, it was probably just straight-up thrown out. Fun fact: Wal-Mart managers aren't' even supposed to answer unsolicited letters. Even if it's a "I am 6 years old and I loved your cookies love Davey" sort of thing made out of crayon and construction paper. Now, the Store Manager CAN elect to answer these sort of things- but generally they won't because word getting back to Corporate about a 'negative action to a guest' can lead to coaching and termination. So, all in all, Chris' letter was probably shit-canned the moment it hit the office.
2. Given the constant rotation of managers in any given Wal-Mart, as others have said, the people running the store probably don't even remember they've ever slapped a Trespass (the official term) against Chris. Five years is an extraordinarily long time when it comes to customer changes, and I can guarantee, I'd be willing to wager actual money, that at least 70% or greater of the employees that were working when he was there have either moved to a completely different department, have transferred to a different facility, or have left the corporation altogether. Managers have to remain in a store for at least two years before they can transfer, and that means at least two and a half rotation cycles have passed since Chris first fucked up there. Again, as others have said, if he were to wander in, do his business, and leave-- even dressed as a clown-prostitute as he is wont to do-- nobody would probably even bat an eye. Further, Trespasses are made at the joint-decision of the Store Manager and the Asset Protection manager. If neither of them or any of the assistant managers are even still at the store, much less even working, he can just check in and out like a human being. No muss no fuss.
Although, another fun fact, whenever a trespass is slapped on someone, they make a file that does get sent to Bentonville, Arkansas (Wally World corporate HQ) and it stays there permanently. So, if Chris goes into any other Wal-Mart and fucks up... well, he could be banned across the entire company. But that's a whole other can of worms I won't even bother yapping about.
So, TL;DR- Wal-mart probably, literally, has no time at all for Chris.