As I'm trying to tell you, assuming malice instead of disagreement isn't productive. It's always been green, even when it was the only option. Perhaps they feel that green is still the best choice!
As others point out, there are accessibility options for people who want more contrast (and which benefit users with trouble reading these outbound messages in far more useful places).
Regardless, they could improve it at any time, yet its been like this for... a decade now? Cognizant Inaction Is Intention. It doesn't matter why it is how it is; they can make it whateverthehell they want, they run the code, they run the org, they got the keys to production, so: fix it!
The original color may not have been malicious, but it WAS DELIBERATE. Every design decision at Apple is deliberate; to assert otherwise is to be revisionist. Cognizant Inaction Is Intention. Its color was deliberately chosen originally; its color was deliberately changed; their inaction in fixing the accessibility issues that change created is Deliberate, because Cognizant Inaction is Intention.
[1] https://d2bs8hqp6qvsw6.cloudfront.net/article/images/750x750...