Welcome to the community! The Cash Flow planner is a great tool to forecast future money in and out events. I'd be happy to share more on this.
The Cash Flow planner was gradually rolled out to every QBO account and is now a default feature in the program. There's no setting available to remove this feature, but once the multicurrency option is enabled, the Cash Flow menu disappears. This happens because the Cash Flow Planner doesn't support multicurrency. Here's an article for your reference: Cash Flow Planner