After X-COM 2, they released Civ 6 and several expansions, X-COM 2 expansions and Chimera Squad.
They didn't have all the team for 5 years on this.
id like to fantasize this is what 5 years of tinkering and developing and xcom style game would be lol. but i assume early dev started then, if not they wouldnt say it in the article.