SUPERHOT is Free at the Epic Store

While you've probably got it figured now, just in case there's any lingering confusion:

Valve did officially note that their concern was with people not purchasing Steam games through the client, and the fact that such practices were increasing [strangely, their comments on the matter didn't make note of the fact that they themselves had encouraged such behaviors by way of their changes in gifting and regional policies, and various off-putting issues related to major sales].

They never brought up fair competition with other clients- and, in fact, their encouraging such a sentiment may actually be illegal; While Steam has the right to manage their own subscription service (of which any storefront selling Steam key licenses are part of) it's generally problematic to directly target or inhibit other businesses.

Naturally, contractual workarounds do exist, such as Epic has done with their 1-year exclusivity agreements or as console companies have done with arranging specific games as console-exclusive, but Steam would still have to arrange such terms beforehand (rather than simply making a matter-of-fact announcement without first soliciting agreement from, or giving proper notice to all involved parties) and, even then, it could* be possible that they'd still be considered as engaging in unfair business practices if their policies are too restrictive on competitors. Though, being that this is US-based, I'm sure the right bribes would solve everything for them.

* (I'm a bit rusty on my business law, but if you'd like to confirm the actual circumstances of such matters for yourself, just look into United States antitrust laws).

Well as I said I'm not aware of that either, but it would make sense if a dev has it free on a steam competitors website, whatever they consider a competitor, that it would be free on steam too, compared to how originally he was asking if epic games is giving a game for free temporarily, then steam would do so as well to match it, which seems impossible to keep up with.

I've seen mobile apps give games like Hitman Go for instace for free for a while, but it maintained a price on steam since it was a giveaway not a permanent free to play game from that point on. Not sure if something like that would carry over the platform too, since sometimes platform features differ and mobile games can make money through adds, pc's can't on steam.

Rather what I was saying is for instance if path of exile is a free to play game on their website, they wont charge money for it on steam. But I don't know if that actually holds true everywhere. I haven't seen any contradicting examples of f2p games outside steam costing money on steam yet with the same version number, updates, etc. I'm sure there's probably some indie devs out there though, and there have to be some older version games that have now been updated and now cost money on steam when you can still find their old version for free.