So now it's over, I've got to ask.
Did they ever stop using Destiny alpha leftovers?
Infamously, Destiny 1 had a bunch of content cut, including the story. Destiny 1 DLC was partially on the disc (people glitched into it) and Destiny 2 was using things shown in early D1 trailers like the European Dead Zone. When I stopped following, (shortly before they "vaulted" content) they were still repurposing old stuff.
And a related question what content never made it?
Again, early trailers and GDC presentations talked about "the swamps of old chicargo", as well as planets and moons that, at the time, you never got to visit. There was also gambling and sparrow racing. Sadly, those original videos seem to be missing from YouTube, or just buried.