It’s a good move, in just wonder about the capacity and wait time.
This is anecdotal: so far for me I've had zero wait time at the EA chargers at Walmart's when traveling in the EV (around the southeast) for the year we've owned our EV. I hook up immediately and I'm outta there in 10-15 minutes. This is because the EA chargers at Walmart charge as fast as 150kW. At over half of the ones I've been to, there are two 350kW chargers. I've never had to wait for one of those (perhaps because charging happens quickly and the EV owner moves on).
As far as capacity goes, that's a real issue. I've seen at most 4 other EV owners charging when I am. If all 8 or 10 bays were to charge at the same time, and up to 350kW each, that'd be quite a load. Perhaps there's already such a huge load pulled by the Wal-Mart store that an extra 3 or 4 mega-watts isn't so much? I don't know.
Perhaps the reason I've seen at most 4 people charging at a time is because they charge fast and move on. And perhaps because EV's aren't as popular in the southeast. Perhaps because in the southeast we're more rural (read: higher percentage of us live in homes we can charge at instead of apartments, thus almost everybody I see at chargers are fellow travelers and not charging for local driving because they live in apartments -- maybe in more urban areas that's not the case). And perhaps the reason I see so few EV's charging is because we don't have bitter cold here (which slows down charging speed and can increase the odds more charging bays will be used simultaneously).
You get to go buy Walmart or Sam stuff while waiting for the charge. I’m not a fan of electric cars, but this is a brilliant business decision.