In what sense? Aside from whether it's practical to really desire nothing, if you could wouldn't you be free by definition because you could do and have absolutely everything you wanted, that being nothing?
As someone who is driven to create, this is just not true for me. I am constantly wanting this or that in order to create something magical. Just accepting what is, does not lead to creation. Being creative is freedom for me.
I think there's an important distinction to make with this: contentment vs complacency. They're similar, but distinct. Contentment resonates more with the gratefulness aspect of your statement, whereas "wanting nothing" leans more toward complacency. Contentment is more oriented with a sense of joy or peace, whereas complacency is apathetic and numb. Only one of those sounds like freedom to me.
In addition, I would argue that it's impossible for a human to truly "want nothing" (sorry Buddhist friends). Even the most enlightened soul would desire to see peace throughout the world. In fact, if you truly wanted nothing, I don't think gratefulness would even be possible--what is there to be grateful for if you didn't want any of it in the first place?
I certainly haven't figure out how to be happy without being grateful. And I've noticed comparison seems to serve little purpose other than to undermine gratitude.