If you read the text of the article, what the op has written is...

If you read the text of the article, what the op has written is out of context.

The
“I made that decision sort of spur of the moment because it just came up...."

was in relation to him having challenged Julie Bishop for the deputy leadership of the Liberals.

What he is saying is that he would consider throwing his hat in the ring again if the leadership was vacant but wouldn't set out to instigate a challenge.

So if the Coalition lose the next election and Turnbull resigns you might see him challenge against other contenders.