Sasori would have hunted down and Kill Kakashi if he found out Kakashi's parents were the one that killed his parents. Why didn't they make a filler of it yet? So many
Sasori's Mother Friends - Comic Vine
Why did Sakumo kill Sasori's parents? - Quora
Sasori no Akasuna
Naruto: How did Sasori Join the Akatsuki? Puppet Master's backstory, explained
Was there anyone besides Granny Chiyo that could defeat Sasori? - Quora
Who are the parents of Sasori in Naruto? - Quora
Sasori is arguably in the top 5 strongest Akatsuki member, yet people underrate him. He has the 2nd highest data book ranking in Akatsuki after Itachi. He didn't lose to Granny Chiyo