That is such a load of shit. The cost of digital is a problem and the shift to digital is limiting the number of physical copies so there is usually closer to a shortage than a surplus. They figure most will buy digital if they can't find physical. I mean it is a smart strategy, it just comes at the expense of consumers which is basically the point of business, especially when there is no free market to have competition discourage being a cunt.
And that is a switching strategy. Whether it's purposely done, or accidental can always be argued. Although IMO, it's done on purpose.
It's really no different than when you see something in the weekly flyer for a grocery store. The store wants to fulfill getting product because people want it and will come to the store to get it. But the last thing they want to do is order too much.
A benefit is that if they are short a bit, most customers dont really care and will just accept the store ran out. And much of the time they'll just buy something else at a higher price because they are already there. The chances of a customer being so pissed and never coming back is slim. So either way, the store manager got you into the store.
The same goes for physical games. As you said, if it's not there, people will just buy a dollar card and buy it online, or use their credit card and buy online. So either way that got ya. And buying online is more margin as the digital store owner maxes out the cut.