For anyone who was waiting for them to come back in stock, the Phantom 4 high capacity battery is available here in the DJI Store.
They’ve been in and out of stock a few times today. At the moment, they are in stock. Grab 'em while you can.
Interesting. Out of stock again, but thanks for the heads up about keep trying!
They are back in stock again (for now).
Out again! Somebody must be stockpiling them! 
They are in stock again. If you don’t see this message for hours later (like usual 
), you can also find them here:
https://store.cloudcitydrones.com/dji-phantom-4-pro-intelligent-flight-battery-high.html
In stock at both now! Thank you! 