They're in negotiations for the final 2 seasons... and there's a big difference in pay between the 5 original castmembers and the actresses who play Amy & Bernadette.
No argument that they make good money ($200,000 per episode)... but the others make a million ($1,000,000). Per episode. So they're willing to come off some of that cash to help Mayim and Melissa. Like $100,000 each. Nice.
It's a noble gesture, but not unprecedented--
But after all, Amy and Bernadette have become a vital part of the show. Speaking of Amy, have you seen this??