

Here. And the reddit thread where I found it.
edit: Wait, lemme go ahead and quote the quotes from a previous post of mine:
If we get to a situation – again, this is rare. If we get to a situation where a partner is telling us that the price needs to be lower on other platforms than it is on Steam, then we will typically choose not to run curated marketing during times where that game is being discounted, if that is where the price is lower, or around a launch if it’s a around – if it’s a price at launch time.
and
Q. Okay. And part of these conversations is saying, hey, we’re not going to offer you curated promotions if you keep doing that, right?
A. Part of our approach, if we get to a situation where we can’t have pricing that is fair for Steam customers is not to amplify marketing with curated markets.
Q. But these conversations, as you know, also involve the threat not to keep the game on the Steam store at all; is that right?
A. That is not our typical process.
But those can still make or break a game’s commercial success, especially during release. It comes down to the same thing: Discouraging developers from making their game available for cheaper on other stores. I’m also not entirely sure that they would stop here, considering they said they do this, they did not say “no” to threatening the removal of a game from the store, and there are accounts of developers saying concerning things.