Does the Goblin Boss's Redirect Attack provoke an opportunity attack?

Question

The Goblin Boss's Redirect Attack (MM 166) uses a reaction to switch places with another goblin.

Redirect Attack. When a creature the goblin can see targets it with an attack, the goblin chooses another goblin within 5 feet of it. The two goblins swap places, and the chosen goblin becomes the target instead.

If the Goblin Boss is within reach of a hostile enemy, does Redirect Attack to a Goblin outside of the enemy's reach provoke an opportunity attack?

The Goblin Boss also has Nimble Escape ("The goblin can take the Disengage or Hide action as a bonus action on each of its turns"). If it uses Nimble Escape to disengage on its turn every turn, will using Redirect Attack avoid OAs? Or does Nimble Escape end at the end of the Boss's turn, thus not affecting Redirect Attacks taken as reactions?

For reference, the section on opportunity attacks from the basic rules:

Opportunity Attacks

In a fight, everyone is constantly watching for a chance to strike an enemy who is fleeing or passing by. Such a strike is called an opportunity attack. You can make an opportunity attack when a hostile creature that you can see moves out of your reach. To make the opportunity attack, you use your reaction to make one melee attack against the provoking creature. The attack occurs right before the creature leaves your reach.

You can avoid provoking an opportunity attack by taking the Disengage action. You also don’t provoke an opportunity attack when you Teleport or when someone or something moves you without using your Movement, action, or reaction. For example, you don’t provoke an opportunity attack if an explosion hurls you out of a foe’s reach or if gravity causes you to fall past an enemy.

Answer 1

Yes, if the second Goblin is not within the Reach of the thing making the opportunity attack

It seems a bit weird, however the criteria for triggering an opportunity attack are:

1. You are moving out of the reach of a hostile creature
2. This movement is from one of your Actions, Bonus Actions, Movement or Reaction
3. You have not taken the Disengage action
4. You are not Teleporting

For this question we can discount Point 4, as the Goblin Boss can't teleport.

We'll also ignore Disengaging for now.

For Point 2, the movement is by the Goblin Boss' Reaction, which fulfills that criteria

For Point 1, if the swapping with the second Goblin does not cause the Goblin Boss to leave the Reach of any hostile creature, it will not trigger an Opportunity attack. In the diagrams below, the first set of movement will not trigger an opportunity attack, while the second set will.

EG    ->    EB
B           G


EBG   ->    EGB

E - Enemy; 
G - Goblin; 
B - Goblin Boss  

Note that wherever the second Goblin is moved from, it does not trigger an Opportunity attack from anything as its movement is forced by the Goblin Boss.

As for using Disengage (via Nimble Escape), it only stops OAs for the rest of your Turn, not the entire Round.

So, if someone had Readied an action to hit the Goblin Boss when the Boss did a specific thing, then the Goblin Boss did that thing on the Boss' turn, and in Reaction the Boss used Redirect Attack, that would not trigger an OA, wherever it moved, as it is still the Boss' Turn so Disengage is still in effect. But normally, Disengage would not help for this.

Answer 2

Quite the opposite, it can Redirect your opportunity attack

Attack resolving is atomic in D&D 5e. When you make a single attack (not to be confused with an Attack action), you normally either hit and do damage or miss. You can't interrupt the attack, make another action in-between, and then "finish" the hit. When someone successfully interrupts your attack, you effectively waste it, you can't finish the attack after the fact.

So, when you start attacking the Goblin Boss, and it swaps places with another goblin, you can't just make another attack and then finish your fist attack. On the contrary, the Redirect Attack feature probably can save a Goblin Boss from your opportunity attack. You are "a creature the goblin can see" and you "target it with an attack" when you making an OA. Just keep in mind that Redirect Attack is a reaction, therefore, can be used only once until the Goblin Boss's next turn.

A DM can say otherwise

The Redirect Attack feature description are very concise. It even doesn't say the second goblin must not be incapacitated. A DM may apply any reasonable restrictions they think are necessary.

Rules as written, both options are valid:

You also don't provoke an opportunity attack when you Teleport or when someone or something moves you without using your Movement, action, or reaction.

Redirect Attack is not Teleport, it moves the Goblin Boss and uses its reaction, so it might provoke the OA. On the other hand, this ruling virtually "turns ability into a liability", rendering the Redirect Attack feature almost useless.

Answer 3

The effect "swap places" does not equate to movement. No opportunity attack is triggered.