I dont think Kwan's WD in 2006 affected anyone. She was never really a favorite that year, and it is not like her injury incurred at the Games. It was obvious even to a blind man she had shown up at the Games injured, and probably shouldnt have been there to begin with, but badly wanted to skate in a final Olympics and try one last time for the elusive gold. So the fear of injury wouldnt have popped up beyond normal from her either IMO.
I think for Slutskaya and Cohen it was more a now or never, and both knowing what the Olympic Gold might mean to their career. Irina knew an Olympic Gold might elevate her above Kwan as the best skater of their era. It would also make her a hero for life in Russia, she already was to an extent, but she could probably get anything she wanted forever if she won Russia's first OGM after all she had already done for them. For Sasha an Olympic Gold would make her a legend in U.S skating (I know Sarah Hughes, and to a lesser degree Lipinski are not, but Sasha is different than they are in that her skills were beloved and praised for years but without the major title to justify her being a star) and star for life, and also make her career a success rather than the dissapointment it had been to many people by then. Both skaters knew they werent going to get another real shot at the OGM. Yeah Sasha was 21, but she never really loved to compete like Michelle and Irina. I am sure she knew she wasnt ever going to 2010, and even if she did Asada and Kim were already setting the skating world on fire doing jumps the top seniors were hardly ever attempting, so the writing was on the wall as far as any 2010 OGM prospects.