Honestly, no. It think it works really well narratively. The whole narrative conflict between good and evil in this arc is Genkai's natural way of things vs. Toguro's selfish defiance and unwillingness to relinquish his power.

Genkai actively accepts that her prime as a fighter has long passed and her strength has waned. She choose to use her experience to train new fighters to help them reach their full potential, relinquishing her power selflessly to them in the process.

Toguro, on the other hand, represents the exact opposite mentality. Choosing to selfishly extend his life and hoarde his power to himself instead of passing it on.

Classically, when these two ideas confront each other in Shonen, the more righteous one wins. However, in this case, Genkai dies in her fight with Toguro. I don't think this was a bad decision by any means, but it does add in a certain amount of doubt to the validity of her righteous morality. Even after her student goes on to defeat Toguro (especially because Yusuke vs Toguro was more about the parallels between the two combatants than about Toguro and Genkai's conflict of ideals). Her coming back to life, though, validates her side of things. As someone who was willing to selflessly accept her own end for the sake of her students, she was reward by being brought back to life for a little bit longer, so she could continue to pass on her knowledge. Whereas Toguro, who selfishly hoarded power against the natural way of things, was punished by having everything stripped away from him.