I love the old Raids from Destiny 1 (Vault of Glass is still my fav. Raid and Vex Mythocast is still the best Raid Exotic), i would love to bring them back to Destiny 2 with the Infinite Forest. The story could be that the Vex wants revenge for that you killed the Panoptes Mind back in the Curse of Osiris DLC and the Vex goes back in time to delete the moment you defeated Atheon in the Vault of Glass which is basically one of the first moments YOU encountered the Vex, now you need to go back in time in the Infinite Forest to defeat Vault of Glass again with some differences and higher difficulty since last time. All the old VOG gear is back with the Fatebringer, Vex Mythoclast etc. Now that you can put mods on weapons and masterwork weapons so it would be different. I would love this and to play Vault of Glass again, it was my first raid back in 2014 and is still my favorite raid. The Vex would then after defeating them in the Vault of Glass again go back to Crota's End, then TK Raid and then Wrath of the Machine where you would defeat the Time Traveling Vex for good to stop them from attacking your past.
-
You don't even need a good excuse for it. Have Zavala say something about how Osiris and Rasputin are being more cooperative, and want to run simulations of your most dangerous opponents (Atheon/Crota/Skolas/Oryx/Aksis) to both see what happens and what might happen if different modifiers are applied (Osiris' stake) and to add it to his predictive algorithm (Rasputin). From here, you can access any of the four raids and maybe Prison of Elders through the Infinite Forest, which are just straight ported from D1 with some slight adjustments to take into account new mechanics from D2. Each week has a featured raid with prestige modifiers in it, which are just stuff like Glass or Blackout or Heavyweight if they want to be easy, but it gives you better drops, such as doing the featured version of Vault of Glass gives you a chance at Mythoclast. The Forest exists, Bungo, use it.