I think they fixed it now because it does indeed link to the new (2C) version. Or they just decided to send you the old one?
About Lithium Polymer it’s all about preference, if safety if your primary concern then definitely stick with 18650 versions, which are marketed 10,050 and 20,100mAh respectively and have sightly lower energy rating. They have light blue LG F1 cells inside which according to discharge tests yield approx 3,200mAh.
Xiaomi has now released a Mi powerbank 3, same capacity same form factor, but now supports Power Delivery output up to 45W and costs about $12 more.
Both banggood or gearbest pricing are not so worth it for me now that a official Xiaomi store has opened in my town. The updated 10,000mAh version with 2 USB ports sells for $16 and the 2C goes for $25. And all of the other accessories are also much cheaper by a considerable margin.
I have also found that many “Xiaomi” branded accessories are also sold under the ZMI name, some of them being just 1/3rd of the price of banggood. Search zmi on amazon or go directly to their homepage and you’ll find some great deals.