"I was told that the show had too many characters and that they needed to downsize because they couldn't service all of the characters effectively," Drew told The Hollywood Reporter of the reason for her exit. "They didn't want any of us to be left in the background and not getting much of a story."
"Because there were so many series regulars, they needed to downsize and to find some characters that they felt like they could tie up their stories well," she added.
"Krista Vernoff said that she felt like April had been through so much and had come out the other side and that she didn't know what she could put her through again," Drew said. "It was really hard to hear that. But Krista had a lot of very complimentary things to say about the work that I had done — especially this past season — and that April was going to have her happy ending."
April indeed found her happy ending, reuniting with her ex-fiance Matthew Taylor (Justin Bruening) and getting impromptu married in an intimate ceremony during the season 14 finale, after it was revealed April had quit her job at Grey Sloan Memorial to do "God's work" helping the needy.
"... there was something beautiful about the redemption story between April and Matthew," Drew told the outlet. "She hurt him worse than anybody had ever hurt him by walking away from him [at their wedding]. For there to be reconciliation from that scenario? That's a really beautiful redemption story that there could be forgiveness there. He lost his wife and then find his first love again. It's lovely."
While most of April and Matthew's reunion was left off the screen, Drew admitted she could see the beauty of her character's final arc. However, there is another relationship on the show that will leave her wanting more.
"... part of me will always be a little heartbroken that April and Jackson (Jesse Williams) were not end game," Drew said.
Despite her exit, Drew said she would "maybe" be open to returning to the show as a guest star, and even behind the camera to direct an episode.
"April's story throughout the whole nine years on the show was a story about someone going through pain and emerging in a more beautiful, more glorified state of hope and of gratitude and of resilience and of strength," Drew said. "That's what I hope people take away from April."
Grey's Anatomy returns for its 15th season with a two-hour season premiere Thursday Sept. 27 at 8 p.m. ET on ABC.