What does Conway's law state?

Conway's law says a system's boundaries follow the communication lines between teams. This is why service boundaries should match team ownership. The "inverse Conway manoeuvre" uses this on purpose: you shape the teams to get the architecture you want.

"Adding people to a late project makes it later" is Brooks's law, not Conway's. "A distributed system cannot be consistent, available and partition tolerant at once" is the CAP theorem.