From the opinion piece:
Last year, I pointed out how many big publishers came crawlin’ back to Steam after trying their own things: EA, Activision, Microsoft. This year, for the first time ever, two Blizzard games released on Steam: Overwatch and Diablo 4.
Yeah but while they’re not allowed to be on sale within X time of launch, I’ve seen games be part of variable discount bundles or run coupon systems before. Clearly Steam isn’t investing infinite resources into tracking this, and probably doesn’t actually care for anything but AAA games.
That is assuming the language in the contract even includes such coupon or bundle schemes.