The video game development industry already makes extensive use of contractors, dedicated outsource studios in various disciplines (art, audio and QA being the most common), and "support" studios (internal or external studios that work on large, cross-functional parts of a project). While I can see this increasing, the majority of the staff on the larger projects are not full-time staff at the "lead dev" studio but fall into one of the aforementioned categories.
I wouldn't mind seeing broader unionization in the video game industry - it already exists in some European countries - but I don't see it as a panacea to the issues often associated with it. Collective bargaining wouldn't have prevented a company like Activision Blizzard from making a strategic decision to move in a different direction, a direction that necessitates staff restructuring. Potentially, it could improve severance agreements, work rules, or entry-level pay, all laudable goals, but much of that is orthogonal to what is happening here.