Remember, microservices refers to the architecture of people. It is the emulation of the service architecture found in the macro economy (i.e. businesses buying and selling services with each other without any direct coordination), but localized in the micro economy of a single business.

There is a prevailing idea that large organizations do not have the communication capacity for many people to all work together, believing that more people require more meetings to coordinate, which at some point reaches a critical mass where any change requires more meetings than there is time in the day. Teams emulating the macro economy – a world where you can't get Google on the phone no matter how hard you try, where all you get is written documentation – is thought to be the solution to that problem.

So there would be something novel about multiple, disparate teams showing they can all work together under direct coordination while actually getting things done and not get bogged down in endless meetings. But, while the article is light on details, it appears that they actually did stick with a microservices model – creating a copy of Instagram so that the Threads team could provide an independent service without needing to communicate with the Instagram team...