Trusts would be a very extreme case of consolidation, and if Microsoft were to qualify (they're close), it's certainly not because of its presence in video games.
I don't think I'm being charitable at all when I say these old games are dormant IPs. Star Wars Episode 3 was only a handful of years old when Disney bought Lucasfilm, and they were still making all sorts of merch and other products. Actually dormant IPs would be things like Metal Arms and Tenchu. They're not powerhouse franchises, but they're fodder for porting to modern platforms and bolstering Game Pass. Activision is reluctant to revive any of this stuff because it's money that could be spent on Call of Duty.
As to your last paragraph, it was inevitable, but we've been slowly trending toward getting that diversity back in the industry. It may not hit your town specifically, but the Devolvers, Paradoxes, TinyBuilds, Embracers, and Anna Purnas of the world are finding success catering to the customers the mammoth AAA companies abandoned.