The optimal A340 route for YYZ-DEL will head N/NE from Toronto over Iqaluit in Nunavut, then over Greenland and the Arctic, hitting Europe near Murmansk in Russia and then south crossing Uzbekistan, Afghanistan, Pakistan and finally into India near Amritsar.

I guess at this point it depends on your definition of "Transatlantic".

One view is that a transatlantic flight is one that crosses 30W longitude, which this flight indeed does.

Another is that a transatlantic flight is one that utilizes an oceanic track assigned by Gander/Shanwick control, which this flight will not.

I tend to subscribe to the latter view and hence would agree with you that the flight is "transpolar" or "transarctic" if you prefer.