I think more of a gap between the two 13" pro models is desirable - what extra are you really getting for your money going for the 28W model currently? Two ports and a bit more thermal headroom? For $300? Make the $1,799 model closer to the 16", even if the price goes up to $1,999 to cover adding a GPU and 512GB.
I assume they want to make room for the Air to get upgraded, but still stay under the MBP family. Let the Air move up to a last few gen quadcore CPU, but no dGPU. Similar to how Apple handled the iPad upgrade with an older, more powerful, but lower cost CPU, and kept it under the iPad Pro running the latest hardware. So the Air gets more powerful, but there still is a distinct jump to the Pro line.