While an MDM can limit what apps are allowed (or not allowed) the most simple usage is to tag company owned data.
This way if someone leaves the company with their personal cellphone, the MDM policy can wipe out anything tagged as company property.
@JaredBusch thanks for clarifying the point, that this policy is under the security settings. The app is moot to the policy being there or not if one exists at all.
To clarify further, there were no MDM policies set under Device Admin outside of what O365 already applies. I did remove that but that caused it to log out of the account/remove it and when I reconnected things, the problem went away as I anticipated. Still was curious as to why it was happening though. My best guess is what I previously mentioned about him connecting to an open hotspot and it causing the issue.