I see a couple of problems with classifying "intelligent design by machines" as a big evolutionary leap away from "intelligent design by humans".

The main difference is one of performance. Performance has been increasing gradually anyway - what is happening now is that it is now increasing faster.

Also, humans routinely augment their intelligence by using machine tools - blurring any proposed line between the machine-augmented humans that we have today and machine intelligence.

My favoured evolutionary transition classification scheme is to bundle all the modern changes together - and describe them as being the result of the rise of the new replicators. Machine intelligence is just the new replicators making brains for themselves. Nanotechnology and robotics are just the new replicators making bodies for themselves.

These phenomena had a single historical source. Future historians will see them as intimately linked. They happen rapidly in quick succession in geological time.

If you want to subdivide further, fine - but then I think you have to consider the origin of language, and the origin of writing and the origin of the computer to be the next-most important recent events.