Not qualified to comment in any way, but...
Turboprop and turbofan engines may look very different, but if you think about it, are more similar than people think.
Take a turboprop, add a load of extra blades, put a shroud around the whole thing to cut the noise down on the noise and it starts to look a lot more life a fan engine.
Most of the thrust in a modern turbofan is generated by the fan at the front, rather than the air actually passing through the core of the engine, so in a way this is acting like a large propellor. I think.
Obviously not that simple in reality - variable pitch/constant speed props etc.
What happened to the 'Unducted Fan'? (Turbojet engine with external 'blades' on the rear). Was this an attempt at 'best of both worlds'?