Also, seeing as QR locos don't have a pre-existing class "letter" that most railfans seem incapable of getting over, it will really shake the mindset of many, having no "Class" to attribute to them. I wouldn't be surprised to see some imaginary designation invented for them - "DQR"? "DT"? "DGM"? "DE"?
QR National had this problem in WA with the 2100 class and gave them the class DD. Admittedly these were earlier units with DC generators, but they looked the same until the driving positions changed to the other side.
Since Tasmania seems happy to call the other similar units by their WA classification, why not DD....
Major difference, after initially dispensing with class letter designations, ARG in W.A. officially brought them back (anyone know why they initially dropped them in the first place and why they brought them back, other than the obvious - because they could and because they wanted to?)
Tas. on the other hand, haven't had letter classifications since Track Warrant control was introduced. The only reason they are still referred to is because for some reason, in the Tasmanian context, gunzels seem incapable of letting them go (yet only have no such problems with the ex Patrick (NB) "18" class, for instance) and many Tasrail staff, having a lifetime of referring to locos by classification letters and having no cultural background (unless ex EBR) in numeric only i.d.'s, also seem to have a conservative resistance to the new numeric classes.
Nevertheless, the QR 2150's have no alpha designation, will have no requirement for one, hence will not receive one. So any letter "class" will be as fictional as me claiming the actual class for the M.K.A. rebuilt "2130"s is "ZM".