Although it hasn't yet been one full year since it made the M6 and M6 Plus official, it looks like Gionee simply can't wait anymore and wants to unveil the M6S Plus this month. The Chinese company has started sending invites for the unveiling that will take place on April 24, so next Monday.
You can see the official invite package in the pictures above and below this paragraph. Unfortunately they don't reveal any specific details about the specs of the M6S Plus. However, a fingerprint scanner being included is a certainty as you have undoubtedly realized. We assume the dedicated security chip with ten layers of protection for your personal data, which debuted with the M6 and M6 Plus in 2016, is going to stay.
The "M" series from Gionee, previously also known as "Marathon", has always been about cramming huge batteries into mid-range smartphones, and we have no reason to think this will change with the next installment in the line. The M6 Plus that the new M6S Plus will replace came with a 6,020 mAh cell, believe it or not.