Letting go of your earthly tether, I don't think it directly translates to: I don't give a shit anymore of those I love. The worst thing is that he never mentions her again and her fate was one of the worse in this entire franchise. Her head freaking imploded like a watermelon to concrete inside that metal and all he can spare her is one expression of sadness and then poof, it's like she never existed.

I really loved them as a couple, it was adorable seeing Zaheer go up on his tiptoes just to kiss her. In fact we actually get to know Zaheer and the others much better than all the other villains in LoK so although their deaths were greatly symbolic, I'm also very disappointed that we didn't get to see more of them.