Content takes Time. Money. The game isnt made by a group of robots, its made by people. People typing code for hours at end, weeks at a time. Artist designing all the models, animations and effects that go into something as small as the flash of your weapons barrel to as big as the the raid bosses grand entrance. It was already discussed just throwing a "harder mode" on the raids with stronger enemies, and they stated they didnt want to do that. It was stated by the raid team that if they were to rereleasw the old raids theyd have to do some manor changes to them first on a base level. Changing mechanics, puzzles, and encounters to make them fresh and new. In otherwords, remaking these raids from the ground up. That takes time, the vault of glass was started after beta, it took from the time beta to its release for it to be worked on and even then it was glitchy.