S.T.A.L.K.E.R. 2 developers, GSC Game World, announced they will use Epic Games' Unreal Engine 4 which prompted the fans to immediately start asking questions about possible exclusivity deals. This might be good news for modders though.
GSC Game World attempted to get S.T.A.L.K.E.R. 2 at the beginning of the last decade but it was cancelled twice which caused the series' fans to become disillusioned and give up hope on having another artefact-hunting adventure.
However, a completely new S.T.A.L.K.E.R. 2 project was announced in 2018 which excited some but others were still wary that another cancellation could happen. Furthermore, there was apparently no word on whether GSC Game World would use the same engine as in the previous titles. Technically, there was, but the for some reason and everyone just ignored it until the devs popped up to reiterate it again - .
Normally, it wouldn't really be breaking news now either as many games use UE4 but there was no Epic Games Store and the exclusivity deals back in 2018. Since GSC announced the engine choice, many fans found themselves flustered and started asking whether they are heralding the news of Epic Games exclusivity.
GSC Game Worlds are currently remaining adamant that this is not connected to platform availability and that they would talk more on the matter at a later date.
Some are speculating that GSC are attempting to ease fans into future news of EGS exclusivity but that is all hypothetical at this point. One thing is certain though - with UE4, creating mods in S.T.A.L.K.E.R. 2 should prove easier. That alone is good news for everyone since we could be looking at the equivalent of free DLC for years to come.