Hops are correctable on an otherwise finished wheel, but it does take some skill. Vertical hops require significant spoke adjustments which will feel a bit scary the first time.

A decent vertical hop may take three or more full nipple turns to correct. To do this you need to work in groups of spokes on opposite sides of the hub. A high spot on the rim means you need to tighten the spokes near the hop and loosen the spokes on the opposite side of the hub to pull the rim even without affecting spoke tension or trueness. It may be easier to think in terms of shifting the hub around. A hop in the wheel means you need to move the hub closer to that spot on the rim, hence why you need to loosen spokes opposite the hop to correct it.

I've had the best luck working on a group of four spokes near the hop (32 spoke wheels, lower spoke count wheels may mean only using two spokes) and another group of four directly across from those near the hop (mark the spokes you are working on). The middle two get the most turns and outer two get lesser turns, spreading the 'love' a bit.

As pointed out above, squeezing spokes is better for stress relief than wind-up undoing. It can cause some pinging but compressing the rim or pushing the hub laterally is far more efficient.