The lack of the specific term "incel" and the insistence of him being single and misogynistic in the motive being mentioned by police and politicians is rather telling.
As far as the Australian authorities and Government are concerned, single men are just as much of a terror threat as other well known groups. They're also preparing to interview the perpetrators family as if they are implicit in this tragedy. Expect the Government to take action through new laws and measures considering their assumed background and majority of victims.
Not evidence that might ruin a perfectly good narrative.