Moonlight Sonata would definitely be in their wheelhouse, but I have to agree that it almost seems too safe, too predictable. I don't doubt they would make it brilliant and magical, but it's just a super unoriginal, super safe choice imo. And even though Marie-France adores Gordeeva and Grinkov, I don't think she would agree to this and go ahead with this choice because Gaby and Guillaume would face countless comparisons to G and G, which she must be aware of. A choice like this seems almost against P/C's ideology of coming up with something unexpected and subverting stereotypes of the sport - I think they'll continue in the innovative vein. Even if they pick a classical piece as their Olympic music, they'll pick something less known, something no one has done before in figure skating. Unless Gaby and Guillaume make an announcement, I refuse to believe any sort of rumours of their music picks (esp. when the information comes from Russian forums).
On a different note - Gaby and Guillaume are on their way to Japan. Gotta say, it's an awful lot of travelling for them these days!