From Official Website: “It has been officially announced that Mechwarrior 5: Mercenaries will now be releasing on December 10th 2019 exclusively on the Epic Games Store.
Community Pre-order pilots will be able to access the Closed Beta to access practice missions in November, prior to the games full launch.”
Source: N4G PC Mechwarrior 5: Mercenaries will launch on the Epic Game Store exclusively on 10th Dec