It's stupid, and entirely inconsistent with Jake Solomon's tweet that the volunteer was still alive, which he only tweeted like 6 months ago, so they were well into development of XCom 2 at that point. Their whole idea of 'you never made it out of conventional weapons' is completely retarded. Not only are laser weapons one of the very first research projects in the game, but the gollop chamber to augment the volunteer is literally the very last step of the game and you can only do it after you have completely dismantled every aspect of the alien invasion and mastered all of their technology, as well as having developed the volunteer to the very pinnacle of his psionic potential. If 'you never made it out of conventional weapons' than you never made a volunteer in the first place.