What does it mean when a feature is in beta or slowly rolling out?

Beta features are newly developed and released gradually to Riverside users, which means you may have access to some features before others do. This phased rollout allows us to monitor performance, gather feedback, and catch potential issues before the feature is made widely available.

Beta features are denoted by the following in a Help Center article:

Please note:
This feature is in beta and is being released gradually to Riverside users.