I don't think they'd go that far, at least not if they can help it. The gift cards are a small profit game, but it's an easy profit as you don't have to carry inventory and nothing to clearance for a loss later. If it gets people into the store, even just to use the rewards certs earned on buying the GCs, which you can't use on the GCs anymore so you're going to buy something with a profit margin baked in, it's a win. Especially if it's a lower cost item as oddly enough most of that stuff has a higher profit margin than big ticket items. Plus it gets people looking at other options they may not have considered before - I think there was a thread talking of people who started shopping at best buy for other things. So the marketing worked and got people to come back to spend more money.
Until many people manage to abuse the system, like buy enough gift cards to redeem rewards certs for a free TV, I think earning points is safe. I'm not ruling it out, but I think it'd be a last resort.