I've noticed recently that $5 bills have made a comeback to the majority, if not all BMO ATMs in the GTA.
BMO ATMs ever since I could remember only had $20s. Now, the machines have $5, $20 and $50 bills available and also allow you to select the denominations you want (up to 40 notes per transaction.)
Hopefully this is a trend that continues. TD has begun installing machines that allow you to pick every denomination from $5 to $100 (up to a maximum of 200 bills), and I've also seen Scotia installing machines that has $5 to $100 bills available too.