Seems like reality is settling in.

I mean, it makes sense to me: a team should keep its code well-factored but in a single codebase that's integrated and ready to deploy (as one or more deployable units) for as long as is tolerable/possible.

I think a trigger for splitting a module off from a monolithic codebase would be when its value or resource utilization has become disparate enough from the rest that it deserves its own infrastructure and/or its own maintenance crew.