https://www.anandtech.com/show/14526/usb-if-usb4-coming-in-late-2020
 
AnandTech have shared that the new protocol is expected to manifest in physical, consumer products by the end of 2020. The specification for the next-generation bus is currently on version 0.7, with the USB Promoter Group expecting it to be finalized by this Summer. Then it's just a matter of manufacturers developing new products powered by the latest protocol. USB 4.0 borrows heavily from Intel's thunderbolt 3 technology - which, if you'll remember, was made available as an open specification very recently. Intel's contribution of the Thunderbolt 3 protocol will enable USB 4.0 to achieve speeds of up to 40 Gbps with multiple data and display protocols being able to share available bandwidth. Additionally, USB 4.0 will make use of USB Type-C's interface, ensuring backwards compatibility not only with it, but also USB 2.0, USB 3.0 and Thunderbolt 3. 
 
Higher USB speeds are always welcome so bring it on. 

I remember agony of people who hurry up to replace X99 motherboards in 2015 because USB 3.1 Gen 2 controllers was intentionally delayed to manufacturers of motherboards sell second gen of X99.
But I must say that I was not better, I sit with processors and memory kit in table waiting black RVE motherboard. 
Good because I decide to gave up because she was launched 15 months later.
People even gave up from Rampage V Extreme because MSI had Godlike with USB 3.1 Gen 2... dear god, that was insane decision. 
How many of people use USB 3.1 Gen 2 everyday.
I mean USB Flash 128GB and some External HDD 1TB size...
No one even care among enthusiasts I was not even sure how many made 3.1 Gen 2 devices.
Rare animals. 
But they know how some people feel when one motherboard have support and other motherboard no support, that's tragedy.
People replace at least 2 platforms before start to use them. USB 3.0 Gen 1 is standard with fact that many nice devices and solid keyboards, motherboards are still on USB 2.0. 
But I must say Welcomed to USB 4.0 if motherboard support PCI-E 4.0/5.0 and DDR5.
It would be nice to see first motherboards with support of all new standards. We didn't saw that years.
Now they could be on same motherboards within 2 years from first PCI-E 4.0, then USB 4.0 and DDR5.