The post makes it clear they’re making heavy use of multitasking and you’re isolating just one task then saying the CPU is overkill. I don’t think simultaneous note taking, Airplay display and remote control of a Mac was a solved problem in 2014.
And I think the broader question is “is this functionality worth $1000 to the person using it”, the answer is yes and the specific grade of CPU inside the machine doesn’t have a ton of bearing on that.
He could have achieved all that even with an iPad Air. So again, my question is what is the relevance of the "pro" moniker?
The broader question is "is a desktop grade processor sold with a "pro" moniker being able to perform some basic PowerPoint and screensharing worth the $1000 asking price?"