This is bad advice imo. The new MacBook Pro does not offer the performance of the 5k iMac and "simplification" isn't really a convincing argument in that regard then, not for that price.
It's money man. If he doesn't like it he can sell it. It's not like he doesn't sell stuff. And, do you own this gear?
There should be disclaimers from people who don't own this stuff yet offer advice