At E3 2017, Xbox announced that they would be reworking and upgrading their Xbox Live Avatar system and focus more on customization and inclusiveness.
Yesterday, Xbox Wire announced the update would officially be going live for Alpha and Alpha – Skip Ahead Xbox Insiders today, June 19th, by 12pm PDT/3pm EDT.
When the update goes live, Insiders will be able to access the beta Xbox Avatar Editor via the Xbox Insider Hub’s Insider content tab.
Source: IGN.com Revamped Xbox Avatar Editor Set to Launch Today for Xbox Insiders