Use the forest to bring D1 raids into D2 but add some twists, reskin the map and add two or three new mechanics into each of them. Nothing crazy just slightly different. It could give you time for new content while giving players something else to do, make players happy, explain why it's in destiny 2, make Osiris storyline possibly better if you have Osiris be the one to inform you that you need to beat these bosses because those darn Vex are at it again, it lets players have fun when trying out the difference in abilities/supers and maybe players have to come up with new strategies to complete these D1 raids with D2 gear, D1 raid gear with a vex twist also could be added for rewards. Edit: If there is no way for this to happen through the infinite forest or you will not add old raids because of double payment for content, maybe at least continue the storylines of every raid with new full-sized raids and long replayable missions.