Can someone explain in plain English please.

Currently, if you use claude -p (non interactive mode) in for example CI/CD, you can use your included subscription tokens.

They are now changing it to be:

You get $20/$100/$200 of "credit" that can be used for claude -p. Problem is, once you are out of that it is the normal API rates (outrageously expensive).

“All of your favorite Claude harnesses will get dramatically more expensive starting on June 15”