Played some AI Teammates (Elite) on PTR. I have a replay of Tracer being in range of a lone enemy Alexstrasza for 7 seconds and attacking nothing. The Tracer went 90+ seconds without making one basic attack, not even on a minion (although it W Melee twice in that time).
It would actually be hard for a Tracer player to go that long without attacking- you’d normally attack some minions just by walking near them. So maybe the AI bot turned on Hold Fire or something.
I know that AI bots generally don’t attack as much as they should, but this is taking it even farther.