The updates are still only in beta mode for most of OSRS, some of them are easier to apply than others.
Things like the full defence reworks would take months to do with the sheer number of npcs there are in the game so likely won't happen to existing content.
Until the updates are actually out and have been in place for a good amount of time to flush out changes and bugs in the main game for other items, I honestly wouldn't look at them until this time as there are things that will require significant re-writes.
That is ofcourse if the items would fit into the game, it items become to op and are heavily reliant on the defence rework to be "less op" overall it would also be another factor and reason to not add the changes.
