Codenamed Hercules, the upcoming flagship will feature a Snapdragon 855 SoC, triple rear-facing cameras, an in-display fingerprint scanner and wireless charging according to source code information. A renowned leaker has stated that Xiaomi will market the device as the Mi Mix 3s or Mi Mix 4.
https://www.notebookcheck.net/A-star-is-born-Insiders-confirm-that-a-new-Xiaomi-Mi-Mix-flagship-is-on-the-way.420180.0.html