Earlier this week, the Xbox team released a new Xbox One Preview build to members of the Preview Alpha ring, who were invited to give feedback on a couple of new features including a new achievement tracker. This same build is now rolling out to members of the Preview Beta ring, who received their first wave of Xbox One features for the Creators Update during the weekend.
— Brad Rossetti (@WorkWombatman) February 8, 2017
As a reminder, the Preview Beta ring is the second ring that launched with the new Xbox Insider Program. Compared to the Preview Alpha ring, Preview Beta participants will receive slightly less frequent updates (one or two per week) with less risk of encountering bugs.
Microsoft is still not done moving all Xbox insiders to one of the four different Preview rings but the team announced in the Xbox forums that it was currently filling up Preview Ring 3, which is expected to up to three new system updates per month (via Neowin). Just like the Preview Alpha and Beta rings, Preview Ring 3 is invite-only and only Xbox Insiders who provided useful feedback to the Xbox team will get the chance to join it.
Microsoft is still getting started with the new Xbox Insider Program, and it may take some weeks before all members can play with the new Xbox One features coming with the Creators Update. Stay tuned on OnMSFT if you want to know everything about upcoming Xbox One preview builds.Further reading: Xbox, Xbox Insider Program, Xbox One