Perhaps it's both, but we did it at our course under Jim Urbina's watchful eye as it also involved appropriate fairway expansions so the new mowing lines synched with the hole.
I did see photos on this site of a "home grown" effort to have FWs seamlessly transition to bunkers and it did just did not fit well.
When I played SFGC (with Bruce Mosbacher, Tom) back in 2013, he mentioned that SF's greens staff was having maintenance issues with such short grass juxtaposed with bunker edges but we have not found that to be the case.
Our new super (who you also know, Tom) may want to see more of this I believe. It makes a difference. On our 5th hole - a fairly standard 400 yard straightaway par 4, I used to hit driver, aim at right edge of FW bunker (270 out) on left and let my baby fade take the ball to the center. If I pulled it or hit it staight, the rough in front of the bunker would stop it.
Today, the FW rolls right into the bunker and if i dont fade the ball, my second shot is from the bunker!