PCIE is slower than DRAM, so not having DRAM is not a performance improvement, but a hardware limitation reducing the scope of usability. Though it doesn't mean bad - cheaper to produce, serving its own use cases.
Process a stream of data - yes. Machine learning on large set of data - no.
I think what's implied by their marketing at least is that DRAM is included on the chip itself (unlike other solutions like GPUs with external RAM chips)... but the problem is that limits the amount of available RAM quite severely.
Process a stream of data - yes. Machine learning on large set of data - no.