According to the Greek-language site iPhonehellas, quoting a "reliable source inside the Chinese supply chain,” says Apple will start taking pre-orders on the AirPods 2, the AirPower, the iPad mini 5, and a new 9.7-inch (or perhaps 10-inch) iPad on March 22 with the products shipping a week later.
However, according to @onleaks, quoting “a new, but seemingly reliable source” says the AirPods 2 won’t ship until fall, although a wireless charging case for the current AirPods will ship sooner and will work with the AirPower.
iPhonehellas has an unknown track record when it come to predicting Apple releases. However, the Sellers Research Group says that the March 22 date is correct, at least in regards to AirPods 2, the AirPower, and the iPad mini 5. My crystal ball is less certain that the 9.7-inch iPad will be announced at that time.
If you’re not familiar with it, the AirPower — which was first announced almost two years ago — will be able to charge a Qi-compatible iPhone, an Apple Watch, and a pair of AirPods (in a special wireless charging case) at the same time regardless of where they're placed on the pad. AirPower hasn't been priced yet, but guesses have it costing anywhere from $150 - $200. Assuming it actually arrives one day.