Key characteristics of the USB 3.2 solution include:

Two-lane operation using existing USB Type-C cables (USB C cable compatible, devices not yet )
Continued use of existing SuperSpeed ​​USB physical layer data rates and encoding techniques
Minor update to hub specification to address performance and assure seamless transitions between single and two-lane operation


The official release  is planned  (...) in September 2017

news HFR :
http://www.hardware.fr/news/15208/usb-3-2-double-debit-atteint-20-gbps.html
http://www.hardware.fr/news/15255/specification-usb-3-2-a-ete-publiee.html
https://www.nextinpact.com/news/104862-lusb-3-2-grimpera-jusqua-20-gbs-cables-type-c-deja-compatibles.htm