Destiny Content Vault is always there like an unseen predator that Guardians constantly fear but at least it's staying away from 30-Year Anniversary content for the time being.
Ever since the introduction of the Destiny Content Vault (DCV), players of Destiny 2 have been in constant fear, or at least mild anxiety, because their favourite activity, map or gear could potentially get removed until further notice. As such, it's not unusual to see D2 players trying to figure out how long the game's content will be around before it disappears.
This was the case with 30-Year Anniversary content that included a dungeon as well as weapons, some of which are D1 fan-favourites like Eyasluna and Gjallarhorn. Thankfully, the content is here to stay a while longer and those $25 will not go down the drain mere months after the pack's release.
It was Joe Blackburn who confirmed the pack is " not going anywhere anytime soon " upon being asked whether the Witch Queen expansion would be the end of 30Y Anniversary pack. Blackburn didn't explicitly answer the second part of the question though, which pertained to the content staying until the next December.
Whatever the case, you will have more than just a few months to farm those perfect rolls on the new weapons that were made available with the pack.