Blue means the iMessage protocol is being used by all parties. So that means things like end-to-end encryption, data-driven messaging and photos, videos, rich replies, effects, voice replies, etc…

Green means the SMS protocol is being used by at least one person so everything is dumbed down to what SMS can do.

It’s going to stay green, just that green now includes end-to-end encryption as long as all parties are using RMS.

In all fairness, Apple using AI to transcribe podcasts has been a tremendous success. Like, making four or five mistakes across an hour of casual speech. And those mistakes are usually contextual blind spots (like writing “lift” when someone said “Lyft” the company.)