That's not true. Faulty doesn't mean ineffective nor does it mean it's an emergency replacement. There are a lot of "faulty" parts on a typical airliner but safety isn't compromised.
What it doesn't say is why they were faulty. It could be something as trivial as screw holes too big and generally unrelated to the fireproof effects. But for a new build, it complicates things due to the strict certification aspect.
They do this all the time. It's a backup plan for last minute cancellations.
I once won a RU for a cabin that wasn't available only a week prior to the cruise due to a last minute cancellation.
Radiance class has a bar in the lounge, which is wonderful.
Pre-restart they'd bring a mobile bar into the lounge for other ships, but since then we've been stuck waiting for someone to go next door to get drinks.