Nokia never hid this. It is also mentioned on the website that Quickcharge is supported. The phone actually supports only QC3.0 and not 4.0. And it was announced when the phone was announced/launched. Nokia is just not including a QC3.0 charger in the box to reduce the costs of making the phone.
Users are free to use compatible QC3.0 charges and they will see the charging speed go up!
I do not have evidences to support this :)) But I follow Nokia closely enough since countless years. I'm relying on information from Nokia's websites, GSMArena, Qualcomm and some personal tests which I/we have conducted. I might be wrong here.