Ellis, who placed fourth in the Omnium track cycling event at the Rio Olympics, said she was shocked to miss selection in the endurance squad.
"Honestly, at the start, I really struggled with it. It was really hard news to take," she said.
But she saw the positive.
"There is such strong depth in the women's team now," Ellis said.
And she was undetterred, saying she was now targeting the Oceania Championship in October.
"I may as well give it one more shot, I've got nothing to lose now," Ellis said.