Is it a bad idea for somebody to put a work OneDrive account on their personal phone?

Is it a bad idea for somebody to put a work OneDrive account on their personal phone? If they have a personal OneDrive account and also a work provided OneDrive account, and wanted to have them both on their cell phone, but they don't want work to have access to their personal account.

Would they be able to somehow see what's on the personal account files if they really wanted?

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