Theoretically, yes. You’d have to make sure the solar panel gets enough is large enough and that it’s able to store enough energy for night time/cloudy days. I don’t know enough to give you any specifics on what size panel you’d need to buy, but certainly it can be done.
They’ve already said that won’t be part of the plan for V1 of the outdoor cameras, but you can buy aftermarket solar panels which connect to the USB charging port.
Here’s someone who did it with the Pan camera: 100% Solar Powered Wyze Cam Pan