I would argue that there's an issue with deliberately excluding anything for purposes of DLC. I mean at the same time we're talking about pricing and older games, but there was a time many games were designed (shocking, I know) to be the best possible game upon release. Look at the greatest N64 games for example. Ocarina of Time did get Master Quest, but it was a masterpiece as it was. It was the best game they could possibly make, at release. It wasn't, what can we hold back and charge people for later.
I know, I know. Not PC, but you get the point. The idea of holding back content for a game to try and charge more later is at best disingenuous. You're not really getting the finished game, you're getting part of the game and they'll charge you later for what they left out. I mentioned 6 months as a minimum not to applaud that either, but as the earliest I could see the argument being made that they couldn't fit that content in for various reasons. A more reasonable approach would be like Diablo 2 did, when their expansion released around one year later.
I think part of the issue is that an expansion is a chance to really improve the game experience as a whole. An almost immediate expansion release can't do that, it is just more of the original game. I get why they're doing a cash grab, but that's all it is. It's excluding content from the original game.