I can confirm this, and add to this in slightly more detail. Retreating is not the same as your active Pokemon changing. Zoroarks Stand In ability switches it with your active Pokemon, but you are not performing the action of "retreating". So if that Zoroark uses its ability, then it can still retreat, which is a strategy that has used with the card in the past.You are limited to the action of "Retreating" your Pokemon once per turn, but you can use any number of items, abilities, or other cards that switch your Pokemon in a turn.
I can confirm this, and add to this in slightly more detail. Retreating is not the same as your active Pokemon changing. Zoroarks Stand In ability switches it with your active Pokemon, but you are not performing the action of "retreating". So if that Zoroark uses its ability, then it can still retreat, which is a strategy that has used with the card in the past.