https://www.gamespot.com/articles/you-can-pre-order-switchs-nes-controllers-now/1100-6461877/

Nintendo's NES-style Joy-Con controllers for Switch are available for pre-order. However, there are a few considerations to think about before you decide to buy one.

To pre-order these controllers, you need to have a subscription to Nintendo's new Switch Online service. You can't sign up for the free seven-day trial and pre-order the controllers; you need to be paying for a subscription. The subscriptions cost $4 / £3.50 for one month, $8 / £7 for three months, and $20 / £18 for 12 months--which you can pay for with My Nintendo points if you prefer.