Explanation
Spine nodes are core nodes on the fabric network, but they do need to support VXLAN in some scenarios.
According to the Data Center Networking: What It Is, Why It Matters, And Types article, VXLAN is a tunnel encapsulation technology that allows overlay networks to be created on top of the underlay network. Spine nodes need to support VXLAN when they act as gateways between different overlay networks or between overlay and underlay networks.

Explanation
The CloudEngine 16800 MPUD switch does not have a built-in intelligent processing chip. According to the CloudEngine 16800 Series Data Center Switches Datasheet, CloudEngine 16800 MPUD switch has a built-in management chip that provides management and control functions, but not intelligent processing functions.
The intelligent processing chip is embedded in the CloudEngine 16800 AI chip card (AI-NPU), which provides AI-powered network analysis and O&M capabilities.