Calling this a DPU is ridiculous. A main CPU is a data processing unit. This is an I/O processor, not a data processor. It takes one or more communications channels and handles their I/O processing. They handle blocks of data, multiplexed, typically, via the IP header (which is just a mux header anyway), so let's call this a block multiplexor channel. And since it's a processor, its API consists of calling programs that run on it, so let's call the API Execute Channel Program, EXCP. Heck, you could offload disks onto these too; it's not as if they were lame little byte multiplexors, though one might make the argument that a packet is just serial bytes and thus that's a better name.
Maybe this is such a great idea that IBM should acquire Marvell too. A great fit for those Power10 processors that support persistent memory, meaning mass storage devices that are directly addressed by byte, not needing a file system.