Update needed for Technique ARIA22 example "Using role=status to Provide Status Message on Shopping Cart"?

[detlevhfischer]

Hi,
It seems that the example referenced in Technique ARIA22 Using role=status to Provide Status Message on Shopping Cart does not work, maybe because of changes to the claimed default value aria-atomic of role=status.
According to the Technique, the output should be "Shopping Cart # items" or "# items".

<p role="status"><img src="shopping-cart.png" alt="Shopping Cart">
<span id="cart">1</span> items</p>

Current output however is:
---> NVDA/FF: exposes number only
---> JAWS/FF: no output
---> JAWS/Chrome: output "2 items"
---> VO/iOS: output "shopping cart 2 items"

Adding aria-atomic="true" after role="status" in the devtools achieves the desired output "Shopping cart 2 items" (only tested in NVDA/FF).

[JAWS-test]

The support of the alt attribute within Live Region is not good: FreedomScientific/standards-support#299

[alastc]

Is this a straightforward update to the technique? If someone can make a PR, it looks like a simple thing to approve.