If our servers are on defender for cloud will copies of some files be upload to MS?

[MrJohnson1905]

We have data that is not allowed off site. 

[#2]

Depending on service you are using data might be store in Microsoft Servers.
What data are you referring to?
You could manage it in on-premises method and keep your data locally but for some data and not all.

[#3]

Sorry to give vague answers.
The defender solution will be entirely cloud based. we will have local servers (when they become end of life we replace them with a cloud based service). In the meantime we need a solution where our data is not uploaded to Microsoft. We have identifiable medical data and are subject to legislative requirements

[#4]

Please take a look: https://docs.microsoft.com/en-us/azure/defender-for-cloud/data-security

[#5]

Microsoft Cloud is compliance with GDPR and also there is a website for Microsoft Cloud on Healthcare, have a look at:
https://www.microsoft.com/en-us/industry/health/microsoft-cloud-for-healthcare'
To learn more about privacy, have a look at:
https://www.microsoft.com/en-us/trust-center/privacy
To learn more about compliance, have a look at:
https://www.microsoft.com/en-us/trust-center/compliance/compliance-overview