Since i know most of you dont stay up to date with the blog posts
The best part -
"They could however gain access to Fairy Rings or Darkmeyer, as none of the pre-requisites for these have a hard Defence requirement. There are other items that might fall outside of these restrictions - such as the Heavy Ballista - that we'd be more than happy to poll as part of the Community Consultation process to address concerns around balancing, especially with respect to PvP."
https://secure.runescape.com/m=news/an-update-on-official-account-builds?oldschool=1
also regarding being able to complete every quest @K2P
"We also saw a handful of concerns around 1 Defence Pures gaining access to gear or spellbooks that would offer huge spikes in power. In case it wasn't clear before, restricted builds will not be able to complete quests or equip gear that they lack the requirements for. This means a 1 Defence pure couldn't complete Lunar Diplomacy because it has a hard requirement of 40 Defence. Similarly, they wouldn't be able to equip Barrows Gloves as they require 41 Defence to do so."