The sample dialog says :

"Are John and Mary still living in New York ?"
"No, they [have] just moved to Dallas."

Is it also right to put "No, they [had] just moved to Dallas." ?

Question

The sample dialog says :

"Are John and Mary still living in New York ?"
"No, they [have] just moved to Dallas."

Is it also right to put  "No, they [had] just moved to Dallas." ?

Answer

"They have moved" puts the action in the past.

"They had moved" puts the action before something else, both in the past.