Although The Elder Scrolls IV: Oblivion Remastered overlaps with the fan-made remake mod Skyblivion, Bethesda still acknowledged the modders' efforts by giving them code for the new remaster.

Oblivion Remastered has finally come, and with it we've also gotten affirmation that the RPG's long-awaited unofficial remake, Skyblivion, won't be getting any pushback from Bethesda going forward. In fact,

TL;DR: Skyblivion is an ambitious fan remake of The Elder Scrolls IV: Oblivion using the Skyrim engine, featuring overhauled dungeons, environments, and quests after 11 years of development. Bethesda fully supports the project, providing the team with Oblivion Remastered keys and confirming no shutdown plans.