"But here is the real issue that co-packaged optics is facing compared to the pluggable transceiver world. In the pluggable world, the choice of the optics technology is not tightly coupled to the switch chip. They are disaggregated and you can deliver a pluggable module to the market and insert into a platform that shipping in high volume whenever it’s ready."

"In a co-packaging world, you pretty much have to make the choice of what technology you are going to bet on two years in advance. It takes that long to develop these 32 channel slices, and it gives them a chance to iterate and it requires you to spec on Day One. So if you want to do co-packaging today for a 102.4 Tb/sec switch chip coming in 2024, you have to start right now, making commitments the exact design of that, that co-package optic slice. Whereas with pluggable optics, you’re completely decoupled, and if it takes us a year or longer to get it ready, it’s no problem, we can ship that in 2025."

https://www.nextplatform.com/2022/03/10/talking-silicon-photonics-signal-and-noise-with-andy-bechtolsheim/