I'd agree with this. A few top players have stated that Carlsen is extremely difficult to prepare for, because he's capable of playing a wide range of openings, using obscure variations, and adjusting his play/style towards his opponent.

If you review his games over time, you'll noticed he's become a much more balanced player, capable of playing both extremely dangerous and tactical positions filled with traps, but also more quiet positions that aren't as sharp, but rich with strategic possibilities.

Many players tend to lean towards a specific "style" of play, but Carlsen has a rare gift to be able to adapt a variety of styles depending on his position and opponent.