Some points I’d like to add. In the Court of Oryx, there was a tier 3 Wizard boss. She was a daughter of Savathun or something. She had Scarlett colored armor. Looks just like a Wizard in the Shadowkeep trailer. Perhaps these are Savathun’s actual Hive we’re fighting. Additionally, there was a Crucible map in D1. The Anomaly. It was on the Moon and it’s grimoire card is quite interesting. Anomaly Card: https://www.ishtar-collective.net/cards/the-anomaly Balwur Card: https://www.ishtar-collective.net/cards/balwur
Yes, yes, I did also think about Anomaly while making this post but I couldn’t really draw a connection and I also wanted to look for hints towards Shadowkeep in current lore, because I doubt a D1 Crucible map could serve that function. About the red Hive, they could technically be Savathûns Hive, but they look too much like the Hidden Swarm from D1. Some of the markings are exact matches.