It was from the article on the Civ website https://civilization.com/news/entries/civilization-vi-gathering-storm-new-expansion-release-date-pc-february-14-2019/ It's about half way down, 2nd paragraph under the heading "Taking the World by Storm"
Epic put out a $10 coupon (MEGA SALE 2020 COUPON,) so if you want the improved game features, the Gathering Storm expansion is $9.99 with the coupon.
Always check on isthereanydeal.com for sales. They list prices from about 20 or so different, legitimate sites. Green Man Gaming currently has a small sale on for Gathering Storm (for steam version).
If you must have it now, you can buy the Civ 6 Platinum Edition for just over $40. It includes all DLC except the New Frontier Pass from this year.
https://gg.deals/pack/sid-meiers-civilization-vi-platinum-edition/
I don't have the Epic Games launcher so I can't help with you that, but I do use a little app called Lightshot to take screenshots and it works really well for me. https://app.prntscr.com/en/index.html
NP. If you need any help or advice feel free to PM me. I'm a pretty high ranked player in competitive league play and have a pretty good understanding of the game. you may also want to consider buying this guide from a buddy of mine