[zubat]

This isn't anything new to how the business is structured. Note the elision of the 50+ employees in-house: even if it's one artist and one programmer, you really need them to be full-timers to run the main production cycle, or at minimum longer-term contractors who have time to ramp up. Otherwise you get too many bottlenecks. Outsourcing ports, localization, and audio was done almost from the beginning. (Go look up how Rob Hubbard wrote the soundtrack to Commando on C64 for one example)

That said, the trend definitely continues to lean towards a small core team that can put the pieces together, and then external teams who can leverage a longer term specialization, lowering management risks on both ends by reducing the "seasonal layoff" dynamic of game launches.