For those who have not been tracking this work, Internet2 has completed one of the smoothest and most amazing technology transitions I've ever seen (despite a few unexpected obstacles like a pandemic); the new network is absolutely amazing. This is a very brief, high-level summary of what's been happening and I'd urge member of the CNI community who have not been following developments in this area to spend a few minutes reading this.

https://internet2.edu/internet2-next-generation-infrastructure-operational-transition-to-fully-automated-400g-national-infrastructure-complete/

Clifford Lynch
Director, CNI