A result of Development, these articles are posted by the relevant Developers to enlighten (or attempt to enlighten us) about information in specific updates. These are usually released just before the related Update/Expansion. They cover many subjects, from Warsteeds to Essences to new Crafting Tiers, and more. Below is the link. Please refer to these articles often. They contain much information.
https://www.lotro.com/en/game/articles