Hmm, the general consensus online seems to be that they are. I copy pasted this question to the Dakka Dakka boards and they came back with a definite yes (http://www.dakkadakka.com/dakkaforum/po ... 58163.page
Here is another online discussions accepting that it is a witchfire:http://www.dakkadakka.com/dakkaforum/po ... 17677.page
I think the confusion comes in (and where we stumbled the other day in my game) is that the BRB states there are subsets of Witchfires, then lists Beam, Focused and Novas but only re-enumerates (in the subset descriptions) that Beam and Focused are witchfires. I feel Novas are as well as when describing types of Psychic Powers, the categories are in larger font (Blessings, Witchfires, etc), then immediately following the note that there are subsets of Witchfires, Beam, Focused and Nova are all in italics - indicating they are all subsets of Witchfires. It would obviously be much more clear is they would have just used the word 'Witchfire' in the description of Nova, but you know, GW.