CBA didn't say they've signed a multi year contract, you have misread.
Whether the ASX announcements department viewed the Fantastic furniture as price sensitive at the time isn't the point, it was a material contract to GSW in terms of revenue. Therefore GSW were required to disclose that it wasn't going ahead. If you announce a contract, then lose it, you have to announce it!
You also seem to conveniently ignore the Fruit box contract, which was tagged price sensitive, was lost by GSW and not announced. That makes no sense.
GSW Price at posting:
$2.92 Sentiment: Sell Disclosure: Held