For less than $10 more than the VDSL-only version, Technicolor is selling a unit ready for G.fast when the company deploys. (Broadcom's G.fast chip also does VDSL.) Broadcom wants to seed the G.fast market and is presumably offering a very attractive price for the first generation chips. Less than $10 is a small price to pay for an easy future upgrade.
Karel Adriaensen wouldn't even give me a hint of which telco may be the world's largest buyer of G.fast modems. The telco intends to use the modems for G.fast one day, but they are serving as 35b vectored VDSL modems for now. Adriaensen says G.fast is now ready for large-scale commercial deployment. "Standardization is complete, chipsets are available, operators are evaluating it and the first sizeable commercial deployments are expected to start in 2017 ... Several hundred thousand of those gateways will be deployed around that operator's country, but G.fast will not be enabled until later in 2017."
Technicolor was Thomson/RCA before a reorganization in 2010. Thomson had purchased Technicolor, a leading Hollywood lab, and decided that was a more attractive name. The modem division goes back to Alcatel Micro, which was the DSL leader at the turn of the century. ADSL/VDSL hybrids took years to deliver the promised performance; I have no data this time.