Bethesda's PR team has probably done the first thing right ever since Fallout 76 kicked off and stated that their future games would come to Steam in addition to Bethesda.net launcher. This probably means leaving Epic Games Store out.
Epic Games Store maybe started the platform-exclusive war but now it appears that GabeN and co. are ready to strike back. The first in line for future Steam games is Bethesda apparently, who that DOOM Eternal, RAGE 2, Wolfenstein: Youngblood, Wolfenstein: Cyberpilot and Fallout 76 would arrive on Steam, in addition to their own launcher.
While no Epic Games Store user will shed any tears over the loss of Fallout 76, the rest of the titles all look like heavy hitters for the moment. Cyberpilot may not be as highly sought as the other games, but it is certainly a VR experience that will garner a lot of attention.
Keep in mind that only the digital editions of each game will be available on Steam as all physical editions will still instead. This is not an unusual practice, but it is worth noting for anyone who hoped to get a physical copy of the games with a Steam code in it.
Neither Valve nor Bethesda officially confirmed any arrangements regarding the semi-exclusivity but it is quite possible that the former approached the developer and publisher company and either offered them a guaranteed better revenue split or another way of compensation.
If this turns out to be the case, it will be interesting to see how the PC gaming community reacts as it would mean that Steam essentially pulled the same exclusivity lever Epic did previously, although they could indeed claim it was a move forced by their competition.
Meanwhile, Epic Games recently announced they would ease up on exclusivity deals in the future but there is no exact deadline set on it. Fortnite is still printing money for the company so they could technically keep throwing it at publishers and some developers for the foreseeable future.