Yeah, while a little confusing on first viewing, those are supposed to be First Order Destroyers, as the ‘Final Order’ fleet was still relegated to Exegol. Except for one ship that just left on its own to blow up Kijimi.
Is there footage of this idea? First I’ve heard of it.
Yes there is. Here is MR’s video. It’s one of the first things he shows. Looks like his clip would work as it is (minus some finishing touches), as they are First Order.
Although, it’s worth noting that he is playing Palpatine’s message over all of this. I know we only played a small portion of it. And, personally, I’m only interesting in the arrival to Coruscant.