I can't see or display the Power Pivot tab or features in 16 preview
I enabled it from Options>Advanced>Data, but still I can't manage my data model from this version.
Please advise!

Hi,

According to your description, this may be a known issue, I copied the section here

If you are using a SKU other than Office 365 ProPlus or Office 2016 Professional Plus, the Manage Data Model button on the Data tab will do nothing.

https://support.office.com/en-us/article/Known-issues-in-Office-2016-Preview-9a472f43-96dc-4671-ac32-9c673edf3221

Hope it's helpful.

Regards,

George Zhao
TechNet Community Support