I wonder if something huge was about to be exposed and he's getting out to avoid it coming out?

Maybe he was forced out to protect the rest of the corrupt organisation. It could have something to do with the recent trial of his butler who revealed details of the corruption taking place at the very top level.

Maybe he had a crisis of faith and did the right thing after realising that he does not believe in god anymore and is an atheist.

Maybe his conscience understands that the Catholic Churches stance on contraception, homosexuality, child sexual abuse, women's rights, is causing suffering to millions around the world.

They should go one step further. Shut down the whole corrupt organisation and free up the trillions they have in the Vatican to help people in need around the world.

Tens of thousands of Catholic Churches around the world can be used to home the homeless.
Millions of hands clasped in prayer to a fictional deity can then be freed and put to more practical use.