Should VVT Solenoids be replaced in pairs?

While looking at a Dorman VVT solenoid for my 2011 Skoda Superb 1.8 TSI rockauto throws up this message:

There are typically 2 VVT Solenoids/Actuators per vehicle (one in the left bank, one in the right bank). When one fails, the other is usually not far behind. Manufacturers recommend replacing these in pairs.

Is this just marketing or is it really common for both the intake and exhaust solenoids to crap out in a relatively short amount of time one from the other?