I don't know how many corps care about this, but when I did that kind of job, I refuse to have my corp have access to a user's personal data, and be able to brick their personal device, etc. It's not acceptable from a privacy POV and not acceptable from an employee backlash POV. Anyway it was an easy choice because we never had sensitive data that could make it to a phone/tablet. In an environment more like that, I would probably have instituted some kind of privacy waiver that an employee would have to sign in order to BYOD (apple brand). That probably wouldn't fly today, in europe. GDPR and all that.
I say my view of it isn't comprehensive, but a requirement that all devices be under MDM even if those devices don't have access to customer data, is quite an overreach.
Given the general situation with data breaches and so forth, I wouldn't be shocked if, down the road, more and more companies decide that there's just too much risk with BYOD and require employees to use locked-down company-provided devices.